diff --git a/examples/available-phone-numbers-view.php b/examples/available-phone-numbers-view.php
index b72e542f..c119ae16 100644
--- a/examples/available-phone-numbers-view.php
+++ b/examples/available-phone-numbers-view.php
@@ -5,7 +5,7 @@
 $MessageBird = new \MessageBird\Client('MESSAGEBIRD_API_KEY');
 
 try {
-    $phoneNumbers = $MessageBird->availablePhoneNumbers->getList("nl", array());
+    $phoneNumbers = $MessageBird->availablePhoneNumbers->getList("nl", []);
     var_dump($phoneNumbers);
 
 } catch (\MessageBird\Exceptions\AuthenticateException $e) {
diff --git a/examples/chatchannels-create.php b/examples/chatchannels-create.php
index f5359379..1fa88f6a 100644
--- a/examples/chatchannels-create.php
+++ b/examples/chatchannels-create.php
@@ -15,10 +15,10 @@
 // are required when creating a channel for this platform.
 
 $ChatChannel->channelDetails =
-    array(
+    [
         'botName' => 'testBot',
         'token' => '1234566778:A34JT44Yr4amk234352et5hvRnHeAEHA'
-    );
+    ];
 
 try {
     $ChatChannelResult = $MessageBird->chatChannels->create($ChatChannel);
diff --git a/examples/contact-list.php b/examples/contact-list.php
index 32d1cc38..ff41d2c3 100644
--- a/examples/contact-list.php
+++ b/examples/contact-list.php
@@ -5,7 +5,7 @@
 $MessageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 try {
-    $ContactList = $MessageBird->contacts->getList(array ());
+    $ContactList = $MessageBird->contacts->getList( []);
     var_dump($ContactList);
 
 } catch (\MessageBird\Exceptions\AuthenticateException $e) {
diff --git a/examples/conversations/create-hsm.php b/examples/conversations/create-hsm.php
index 6fda1e06..881045d5 100644
--- a/examples/conversations/create-hsm.php
+++ b/examples/conversations/create-hsm.php
@@ -20,7 +20,7 @@
 $hsm = new \MessageBird\Objects\Conversation\HSM\Message();
 $hsm->templateName = 'YOUR TEMPLATE NAME';
 $hsm->namespace = 'YOUR NAMESPACE';
-$hsm->params = array($hsmParam1, $hsmParam2);
+$hsm->params = [$hsmParam1, $hsmParam2];
 $hsm->language = $hsmLanguage;
 
 $content = new \MessageBird\Objects\Conversation\Content();
diff --git a/examples/conversations/list.php b/examples/conversations/list.php
index 5c37408c..b6a9f429 100644
--- a/examples/conversations/list.php
+++ b/examples/conversations/list.php
@@ -8,10 +8,10 @@
 $messageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 // Take 10 objects, but skip the first 5.
-$optionalParameters = array(
+$optionalParameters = [
     'limit' => '10',
     'offset' => '5',
-);
+];
 
 try {
     $conversations = $messageBird->conversations->getList($optionalParameters);
diff --git a/examples/conversations/messages-create-location.php b/examples/conversations/messages-create-location.php
index 769adc73..8d27e06e 100644
--- a/examples/conversations/messages-create-location.php
+++ b/examples/conversations/messages-create-location.php
@@ -7,10 +7,10 @@
 $messageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 $content = new \MessageBird\Objects\Conversation\Content();
-$content->location = array(
+$content->location = [
     'latitude' => 52.379112,
     'longitude' => 4.900384,
-);
+];
 
 $message = new \MessageBird\Objects\Conversation\Message();
 $message->channelId = 'CHANNEL_ID';
diff --git a/examples/conversations/messages-create-media.php b/examples/conversations/messages-create-media.php
index fff236b3..47494583 100644
--- a/examples/conversations/messages-create-media.php
+++ b/examples/conversations/messages-create-media.php
@@ -8,9 +8,9 @@
 $messageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 $content = new \MessageBird\Objects\Conversation\Content();
-$content->image = array(
+$content->image = [
     'url' => 'https://cdn-gc.messagebird.com/assets/images/logo.png'
-);
+];
 
 $message = new \MessageBird\Objects\Conversation\Message();
 $message->channelId = 'CHANNEL_ID';
diff --git a/examples/conversations/read.php b/examples/conversations/read.php
index d2a375df..0f0b36c3 100644
--- a/examples/conversations/read.php
+++ b/examples/conversations/read.php
@@ -8,9 +8,9 @@
 
 // Setting the optional 'include' parameter to 'content' requests the API to
 // include the expanded Contact object in its response. Excluded by default.
-$optionalParameters = array(
+$optionalParameters = [
     'include' => 'content',
-);
+];
 
 try {
     $conversation = $messageBird->conversations->read(
diff --git a/examples/conversations/webhooks-create.php b/examples/conversations/webhooks-create.php
index 08c2e298..43dd949b 100644
--- a/examples/conversations/webhooks-create.php
+++ b/examples/conversations/webhooks-create.php
@@ -13,14 +13,14 @@
     $webhook = new \MessageBird\Objects\Conversation\Webhook();
     $webhook->channelId = 'CHANNEL_ID';
     $webhook->url = 'https://example.com/webhook';
-    $webhook->events = array(
+    $webhook->events = [
         \MessageBird\Objects\Conversation\Webhook::EVENT_CONVERSATION_CREATED,
         \MessageBird\Objects\Conversation\Webhook::EVENT_MESSAGE_CREATED,
 
         // Other options:
         // \MessageBird\Objects\Conversation\Webhook::EVENT_CONVERSATION_UPDATED,
         // \MessageBird\Objects\Conversation\Webhook::EVENT_MESSAGE_UPDATED,
-    );
+    ];
 
     $messageBird->conversationWebhooks->create($webhook);
 } catch (\Exception $e) {
diff --git a/examples/group-add-contact-to-group.php b/examples/group-add-contact-to-group.php
index a6f23b08..46b3dbec 100644
--- a/examples/group-add-contact-to-group.php
+++ b/examples/group-add-contact-to-group.php
@@ -5,10 +5,10 @@
 $MessageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 try {
-    $contacts['ids'] = array(
+    $contacts['ids'] = [
         'contact_id_1',
         'contact_id_2',
-    );
+    ];
     $group_id = 'group_id';
     $GroupAddContact = $MessageBird->groups->addContacts($contacts, $group_id);
     var_dump($GroupAddContact);
diff --git a/examples/group-list.php b/examples/group-list.php
index 3eebb5b0..e6451fa5 100644
--- a/examples/group-list.php
+++ b/examples/group-list.php
@@ -5,7 +5,7 @@
 $MessageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 try {
-    $GroupsList = $MessageBird->groups->getList(array ());
+    $GroupsList = $MessageBird->groups->getList( []);
     var_dump($GroupsList);
 
 } catch (\MessageBird\Exceptions\AuthenticateException $e) {
diff --git a/examples/hlr-list.php b/examples/hlr-list.php
index c35648da..86e56bdf 100644
--- a/examples/hlr-list.php
+++ b/examples/hlr-list.php
@@ -5,7 +5,7 @@
 $MessageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 try {
-    $HlrList = $MessageBird->hlr->getList(array ('offset' => 100, 'limit' => 30));
+    $HlrList = $MessageBird->hlr->getList( ['offset' => 100, 'limit' => 30]);
     var_dump($HlrList);
 
 } catch (\MessageBird\Exceptions\AuthenticateException $e) {
diff --git a/examples/message-create-unicode.php b/examples/message-create-unicode.php
index 0b7b736c..f631fcc7 100644
--- a/examples/message-create-unicode.php
+++ b/examples/message-create-unicode.php
@@ -6,7 +6,7 @@
 
 $Message             = new \MessageBird\Objects\Message();
 $Message->originator = 'MessageBird';
-$Message->recipients = array(31612345678);
+$Message->recipients = [31612345678];
 $Message->body       = 'This is a test message with a smiling emoji 😀.';
 $Message->datacoding = 'unicode';
 
diff --git a/examples/message-create.php b/examples/message-create.php
index 5f5fd498..988282c9 100644
--- a/examples/message-create.php
+++ b/examples/message-create.php
@@ -6,7 +6,7 @@
 
 $Message             = new \MessageBird\Objects\Message();
 $Message->originator = 'MessageBird';
-$Message->recipients = array(31612345678);
+$Message->recipients = [31612345678];
 $Message->body       = 'This is a test message.';
 
 try {
diff --git a/examples/message-list.php b/examples/message-list.php
index 3e207677..c006b9ce 100644
--- a/examples/message-list.php
+++ b/examples/message-list.php
@@ -5,7 +5,7 @@
 $MessageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 try {
-    $MessageList = $MessageBird->messages->getList(array ('offset' => 100, 'limit' => 30));
+    $MessageList = $MessageBird->messages->getList( ['offset' => 100, 'limit' => 30]);
     var_dump($MessageList);
 
 } catch (\MessageBird\Exceptions\AuthenticateException $e) {
diff --git a/examples/mms-create.php b/examples/mms-create.php
index 457b0e50..0d9dd91c 100644
--- a/examples/mms-create.php
+++ b/examples/mms-create.php
@@ -6,10 +6,10 @@
 
 $MmsMessage = new \MessageBird\Objects\MmsMessage();
 $MmsMessage->originator = 'MessageBird';
-$MmsMessage->recipients = array(31612345678);
+$MmsMessage->recipients = [31612345678];
 $MmsMessage->subject = "Check out this cool MMS";
 $MmsMessage->body = 'Have you seen this logo?';
-$MmsMessage->mediaUrls = array('https://www.messagebird.com/assets/images/og/messagebird.gif');
+$MmsMessage->mediaUrls = ['https://www.messagebird.com/assets/images/og/messagebird.gif'];
 
 try {
     $MmsMessageResult = $MessageBird->mmsMessages->create($MmsMessage);
diff --git a/examples/mms-list.php b/examples/mms-list.php
index 1958a02b..5bf94ca1 100644
--- a/examples/mms-list.php
+++ b/examples/mms-list.php
@@ -5,7 +5,7 @@
 $MessageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 try {
-    $MmsList = $MessageBird->mmsMessages->getList(array('offset' => 0, 'limit' => 30));
+    $MmsList = $MessageBird->mmsMessages->getList(['offset' => 0, 'limit' => 30]);
     var_dump($MmsList);
 } catch (\MessageBird\Exceptions\AuthenticateException $e) {
     // That means that your accessKey is unknown
diff --git a/examples/phone-numbers-update.php b/examples/phone-numbers-update.php
index 08bdb464..f2b1e0d6 100644
--- a/examples/phone-numbers-update.php
+++ b/examples/phone-numbers-update.php
@@ -4,7 +4,7 @@
 
 $MessageBird = new \MessageBird\Client('MESSAGEBIRD_API_KEY'); // Set your own API access key here.
 $Number = new \MessageBird\Objects\Number();
-$Number->tags = array('tag1');
+$Number->tags = ['tag1'];
 
 try {
     $NumberResult = $MessageBird->phoneNumbers->update($Number, '31612345678');
diff --git a/examples/verify-create.php b/examples/verify-create.php
index 4a9aab9f..d7aa2179 100644
--- a/examples/verify-create.php
+++ b/examples/verify-create.php
@@ -7,10 +7,10 @@
 $Verify             = new \MessageBird\Objects\Verify();
 $Verify->recipient = 31612345678;
 
-$extraOptions = array(
+$extraOptions = [
     'originator' => 'MessageBird',
     'timeout' => 60,
-);
+];
 
 try {
     $VerifyResult = $MessageBird->verify->create($Verify, $extraOptions);
diff --git a/examples/voice-call-flows-create.php b/examples/voice-call-flows-create.php
index b4e94349..8b7f30d2 100644
--- a/examples/voice-call-flows-create.php
+++ b/examples/voice-call-flows-create.php
@@ -7,12 +7,12 @@
 $callFlow->title = 'Foobar';
 $step = new \MessageBird\Objects\Voice\Step();
 $step->action = 'say';
-$step->options = array(
+$step->options = [
     'payload' => 'This is a journey into sound.',
     'language' => 'en-GB',
     'voice' => 'male',
-);
-$callFlow->steps = array($step);
+];
+$callFlow->steps = [$step];
 
 try {
     $result = $messageBird->voiceCallFlows->create($callFlow);
diff --git a/examples/voice-call-flows-list.php b/examples/voice-call-flows-list.php
index 886ab582..16e890e9 100644
--- a/examples/voice-call-flows-list.php
+++ b/examples/voice-call-flows-list.php
@@ -5,7 +5,7 @@
 $messageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 try {
-    $result = $messageBird->voiceCallFlows->getList(array('offset' => 100, 'limit' => 30));
+    $result = $messageBird->voiceCallFlows->getList(['offset' => 100, 'limit' => 30]);
     var_dump($result);
 } catch (\Exception $e) {
     echo sprintf("%s: %s", get_class($e), $e->getMessage());
diff --git a/examples/voice-calls-create.php b/examples/voice-calls-create.php
index 6b9d9c5a..16cef429 100644
--- a/examples/voice-calls-create.php
+++ b/examples/voice-calls-create.php
@@ -10,12 +10,12 @@
 $callFlow->title = 'Say message';
 $step = new \MessageBird\Objects\Voice\Step();
 $step->action = 'say';
-$step->options = array(
+$step->options = [
     'payload' => 'This is a journey into sound.',
     'language' => 'en-GB',
     'voice' => 'male',
-);
-$callFlow->steps = array($step);
+];
+$callFlow->steps = [$step];
 $call->callFlow = $callFlow;
 
 try {
diff --git a/examples/voice-calls-list.php b/examples/voice-calls-list.php
index 7deb377a..00f495f1 100644
--- a/examples/voice-calls-list.php
+++ b/examples/voice-calls-list.php
@@ -5,7 +5,7 @@
 $messageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 try {
-    $result = $messageBird->voiceCalls->getList(array('offset' => 100, 'limit' => 30));
+    $result = $messageBird->voiceCalls->getList(['offset' => 100, 'limit' => 30]);
     var_dump($result);
 } catch (\Exception $e) {
     echo sprintf("%s: %s", get_class($e), $e->getMessage());
diff --git a/examples/voice-legs-list.php b/examples/voice-legs-list.php
index b718a5a7..e61be0e0 100644
--- a/examples/voice-legs-list.php
+++ b/examples/voice-legs-list.php
@@ -5,7 +5,7 @@
 $messageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 try {
-    $result = $messageBird->voiceLegs->getList('dbf1373c-6781-43c7-bfe4-6538583c444b', array('offset' => 100, 'limit' => 30)); // Set a call id here
+    $result = $messageBird->voiceLegs->getList('dbf1373c-6781-43c7-bfe4-6538583c444b', ['offset' => 100, 'limit' => 30]); // Set a call id here
     var_dump($result);
 } catch (\Exception $e) {
     echo sprintf("%s: %s", get_class($e), $e->getMessage());
diff --git a/examples/voice-recordings-list.php b/examples/voice-recordings-list.php
index 12f773f7..99d962ff 100644
--- a/examples/voice-recordings-list.php
+++ b/examples/voice-recordings-list.php
@@ -5,7 +5,7 @@
 $messageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 try {
-    $result = $messageBird->voiceRecordings->getList('c226420d-f107-4db1-b2f9-4646656a90bc', '4f5ab5f4-c4b6-4586-9255-980bb3fd7336', array('offset' => 100, 'limit' => 30)); // Set a call and leg id here
+    $result = $messageBird->voiceRecordings->getList('c226420d-f107-4db1-b2f9-4646656a90bc', '4f5ab5f4-c4b6-4586-9255-980bb3fd7336', ['offset' => 100, 'limit' => 30]); // Set a call and leg id here
     var_dump($result);
 } catch (\Exception $e) {
     echo sprintf("%s: %s", get_class($e), $e->getMessage());
diff --git a/examples/voice-transcriptions-list.php b/examples/voice-transcriptions-list.php
index 71e8bde4..9c35bf8b 100644
--- a/examples/voice-transcriptions-list.php
+++ b/examples/voice-transcriptions-list.php
@@ -5,7 +5,7 @@
 $messageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 try {
-    $result = $messageBird->voiceTranscriptions->getList('c226420d-f107-4db1-b2f9-4646656a90bc', '4f5ab5f4-c4b6-4586-9255-980bb3fd7336', 'a94f7d51-19b5-4eb8-9e8e-90fce490a577', array('offset' => 100, 'limit' => 30)); // Set a call and leg id here
+    $result = $messageBird->voiceTranscriptions->getList('c226420d-f107-4db1-b2f9-4646656a90bc', '4f5ab5f4-c4b6-4586-9255-980bb3fd7336', 'a94f7d51-19b5-4eb8-9e8e-90fce490a577', ['offset' => 100, 'limit' => 30]); // Set a call and leg id here
     var_dump($result);
 } catch (\Exception $e) {
     echo sprintf("%s: %s", get_class($e), $e->getMessage());
diff --git a/examples/voice-webhooks-list.php b/examples/voice-webhooks-list.php
index 452529aa..6cc31e04 100644
--- a/examples/voice-webhooks-list.php
+++ b/examples/voice-webhooks-list.php
@@ -5,7 +5,7 @@
 $messageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 try {
-    $result = $messageBird->voiceWebhooks->getList(array('offset' => 100, 'limit' => 30));
+    $result = $messageBird->voiceWebhooks->getList(['offset' => 100, 'limit' => 30]);
     var_dump($result);
 } catch (\Exception $e) {
     echo sprintf("%s: %s", get_class($e), $e->getMessage());
diff --git a/examples/voicemessages-create.php b/examples/voicemessages-create.php
index 96d6277a..330e26fb 100644
--- a/examples/voicemessages-create.php
+++ b/examples/voicemessages-create.php
@@ -5,7 +5,7 @@
 $MessageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 $VoiceMessage             = new \MessageBird\Objects\VoiceMessage();
-$VoiceMessage->recipients = array (31654286496);
+$VoiceMessage->recipients =  [31654286496];
 $VoiceMessage->body = 'This is a test message. The message is converted to speech and the recipient is called on his mobile.';
 $VoiceMessage->language = 'en-gb';
 $VoiceMessage->voice = 'female';
diff --git a/examples/voicemessages-list.php b/examples/voicemessages-list.php
index 1fe29430..dab7537d 100644
--- a/examples/voicemessages-list.php
+++ b/examples/voicemessages-list.php
@@ -5,7 +5,7 @@
 $MessageBird = new \MessageBird\Client('YOUR_ACCESS_KEY'); // Set your own API access key here.
 
 try {
-    $VoiceMessageList = $MessageBird->voicemessages->getList(array ('offset' => 100, 'limit' => 30));
+    $VoiceMessageList = $MessageBird->voicemessages->getList( ['offset' => 100, 'limit' => 30]);
     var_dump($VoiceMessageList);
 
 } catch (\MessageBird\Exceptions\AuthenticateException $e) {
diff --git a/src/MessageBird/Client.php b/src/MessageBird/Client.php
index 62cf5065..853ecddb 100644
--- a/src/MessageBird/Client.php
+++ b/src/MessageBird/Client.php
@@ -196,9 +196,9 @@ public function __construct($accessKey = null, Common\HttpClient $httpClient = n
             $this->ChatAPIHttpClient = new Common\HttpClient(self::CHATAPI_ENDPOINT);
             $this->ConversationsAPIHttpClient = new Common\HttpClient(in_array(self::ENABLE_CONVERSATIONSAPI_WHATSAPP_SANDBOX, $config) ? self::CONVERSATIONSAPI_WHATSAPP_SANDBOX_ENDPOINT : self::CONVERSATIONSAPI_ENDPOINT);
             $this->HttpClient = new Common\HttpClient(self::ENDPOINT);
-            $this->VoiceAPIHttpClient = new Common\HttpClient(self::VOICEAPI_ENDPOINT, 10, 2, array(
+            $this->VoiceAPIHttpClient = new Common\HttpClient(self::VOICEAPI_ENDPOINT, 10, 2, [
                 'X-MessageBird-Version' => '20170314',
-           ));
+           ]);
             $this->partnerAccountClient = new Common\HttpClient(self::PARTNER_ACCOUNT_ENDPOINT);
             $this->numbersAPIClient = new Common\HttpClient(self::NUMBERSAPI_ENDPOINT);
         } else {
diff --git a/src/MessageBird/Common/HttpClient.php b/src/MessageBird/Common/HttpClient.php
index b9a03cf7..8a0bb831 100644
--- a/src/MessageBird/Common/HttpClient.php
+++ b/src/MessageBird/Common/HttpClient.php
@@ -28,7 +28,7 @@ class HttpClient
     /**
      * @var array
      */
-    protected $userAgent = array();
+    protected $userAgent = [];
 
     /**
      * @var Common\Authentication
@@ -48,12 +48,12 @@ class HttpClient
     /**
      * @var array
      */
-    private $headers = array();
+    private $headers = [];
 
     /**
      * @var array
      */
-    private $httpOptions = array();
+    private $httpOptions = [];
 
     /**
      * @param string $endpoint
@@ -61,7 +61,7 @@ class HttpClient
      * @param int    $connectionTimeout >= 0
      * @param array  $headers
      */
-    public function __construct($endpoint, $timeout = 10, $connectionTimeout = 2, $headers = array())
+    public function __construct($endpoint, $timeout = 10, $connectionTimeout = 2, $headers = [])
     {
         $this->endpoint = $endpoint;
 
@@ -165,13 +165,13 @@ public function performHttpRequest($method, $resourceName, $query = null, $body
             throw new Exceptions\AuthenticateException('Can not perform API Request without Authentication');
         }
 
-        $headers = array (
+        $headers =  [
             'User-agent: ' . implode(' ', $this->userAgent),
             'Accept: application/json',
             'Content-Type: application/json',
             'Accept-Charset: utf-8',
             sprintf('Authorization: AccessKey %s', $this->Authentication->accessKey)
-        );
+        ];
 
         $headers = array_merge($headers, $this->headers);
 
@@ -220,11 +220,11 @@ public function performHttpRequest($method, $resourceName, $query = null, $body
         // Split the header and body
         $parts = explode("\r\n\r\n", $response, 3);
         $isThreePartResponse = (strpos($parts[0], "\n") === false && strpos($parts[0], 'HTTP/1.') === 0);
-        list($responseHeader, $responseBody) = $isThreePartResponse ? array ($parts[1], $parts[2]) : array ($parts[0], $parts[1]);
+        list($responseHeader, $responseBody) = $isThreePartResponse ?  [$parts[1], $parts[2]] :  [$parts[0], $parts[1]];
 
         curl_close($curl);
 
-        return array ($responseStatus, $responseHeader, $responseBody);
+        return  [$responseStatus, $responseHeader, $responseBody];
     }
 
     /**
diff --git a/src/MessageBird/Common/ResponseError.php b/src/MessageBird/Common/ResponseError.php
index ee8d9e19..a238e48b 100644
--- a/src/MessageBird/Common/ResponseError.php
+++ b/src/MessageBird/Common/ResponseError.php
@@ -26,7 +26,7 @@ class ResponseError
 
     const CHAT_API_AUTH_ERROR = 1001;
 
-    public $errors = array();
+    public $errors = [];
 
     /**
      * Load the error data into an array.
@@ -80,7 +80,7 @@ private function getExceptionMessage($error)
      */
     public function getErrorString()
     {
-        $errorDescriptions = array();
+        $errorDescriptions = [];
 
         foreach ($this->errors AS $error) {
             $errorDescriptions[] = $error->description;
diff --git a/src/MessageBird/Objects/BaseList.php b/src/MessageBird/Objects/BaseList.php
index b229a660..f9e78440 100644
--- a/src/MessageBird/Objects/BaseList.php
+++ b/src/MessageBird/Objects/BaseList.php
@@ -14,12 +14,12 @@ class BaseList extends Base
     public $offset;
     public $count;
     public $totalCount;
-    public $links = array (
+    public $links =  [
         'first'    => null,
         'previous' => null,
         'next'     => null,
         'last'     => null,
-    );
+    ];
 
-    public $items = array ();
+    public $items =  [];
 }
diff --git a/src/MessageBird/Objects/Chat/Channel.php b/src/MessageBird/Objects/Chat/Channel.php
index f2f9f517..f7818b09 100644
--- a/src/MessageBird/Objects/Chat/Channel.php
+++ b/src/MessageBird/Objects/Chat/Channel.php
@@ -78,6 +78,6 @@ class Channel extends Base
     /**
      * @var array
      */
-    protected $_links = array();
+    protected $_links = [];
 
 }
\ No newline at end of file
diff --git a/src/MessageBird/Objects/Chat/Contact.php b/src/MessageBird/Objects/Chat/Contact.php
index 675901d9..e2716d17 100644
--- a/src/MessageBird/Objects/Chat/Contact.php
+++ b/src/MessageBird/Objects/Chat/Contact.php
@@ -38,7 +38,7 @@ class Contact extends Base
      *
      * @var array
      */
-    public $contactDetails = array();
+    public $contactDetails = [];
 
     /**
      * Channel ID.
diff --git a/src/MessageBird/Objects/Chat/Message.php b/src/MessageBird/Objects/Chat/Message.php
index f77fde23..6920b821 100644
--- a/src/MessageBird/Objects/Chat/Message.php
+++ b/src/MessageBird/Objects/Chat/Message.php
@@ -73,7 +73,7 @@ class Message extends Base
     /**
      * @var array
      */
-    protected $_links = array();
+    protected $_links = [];
 
 
     public function getId()
diff --git a/src/MessageBird/Objects/Chat/Platform.php b/src/MessageBird/Objects/Chat/Platform.php
index 3713cc49..dabf07ad 100644
--- a/src/MessageBird/Objects/Chat/Platform.php
+++ b/src/MessageBird/Objects/Chat/Platform.php
@@ -32,7 +32,7 @@ class Platform extends Base
      *
      * @var array
      */
-    protected $contactTemplate = array();
+    protected $contactTemplate = [];
 
     /**
      * The name of the channel details parameter that uniquely identifies a channel on this platform.
diff --git a/src/MessageBird/Objects/Contact.php b/src/MessageBird/Objects/Contact.php
index 281fd8b2..c151eede 100644
--- a/src/MessageBird/Objects/Contact.php
+++ b/src/MessageBird/Objects/Contact.php
@@ -51,7 +51,7 @@ class Contact extends Base
      *
      * @var array
      */
-    protected $customDetails = array();
+    protected $customDetails = [];
 
     /**
      * @var string
@@ -78,14 +78,14 @@ class Contact extends Base
      *
      * @var array
      */
-    protected $groups = array();
+    protected $groups = [];
 
     /**
      * The hash with messages sent to contact.
      *
      * @var array
      */
-    protected $messages = array();
+    protected $messages = [];
 
     /**
      * The date and time of the creation of the contact in RFC3339 format (Y-m-d\TH:i:sP)
diff --git a/src/MessageBird/Objects/Conversation/Content.php b/src/MessageBird/Objects/Conversation/Content.php
index a9ebc17e..a4f21134 100644
--- a/src/MessageBird/Objects/Conversation/Content.php
+++ b/src/MessageBird/Objects/Conversation/Content.php
@@ -76,10 +76,10 @@ public function loadFromArray($object)
     private function loadLocationIfNeeded()
     {
         if (!empty($this->location->latitude) && !empty($this->location->longitude)) {
-            $this->location = array(
+            $this->location = [
                 'latitude' => $this->location->latitude,
                 'longitude' => $this->location->longitude,
-            );
+            ];
         }
     }
 
@@ -89,19 +89,19 @@ private function loadLocationIfNeeded()
     private function loadMediaIfNeeded()
     {
         if (!empty($this->audio->url)) {
-            $this->audio = array('url' => $this->audio->url);
+            $this->audio = ['url' => $this->audio->url];
         }
 
         if (!empty($this->file->url)) {
-            $this->file = array('url' => $this->file->url);
+            $this->file = ['url' => $this->file->url];
         }
 
         if (!empty($this->image->url)) {
-            $this->image = array('url' => $this->image->url);
+            $this->image = ['url' => $this->image->url];
         }
 
         if (!empty($this->video->url)) {
-            $this->video = array('url' => $this->video->url);
+            $this->video = ['url' => $this->video->url];
         }
     }
 
@@ -110,7 +110,7 @@ private function loadMediaIfNeeded()
      */
     public function jsonSerialize()
     {
-        $json = array();
+        $json = [];
         
         foreach (get_object_vars($this) as $key => $value) {
             if (!empty($value)) {
diff --git a/src/MessageBird/Objects/Conversation/Conversation.php b/src/MessageBird/Objects/Conversation/Conversation.php
index d01f3f6e..6a2cd342 100644
--- a/src/MessageBird/Objects/Conversation/Conversation.php
+++ b/src/MessageBird/Objects/Conversation/Conversation.php
@@ -112,7 +112,7 @@ public function loadFromArray($object)
         }
 
         if (!empty($this->channels)) {
-            $channels = array();
+            $channels = [];
 
             foreach ($this->channels as $channel) {
                 $newChannel = new Channel();
diff --git a/src/MessageBird/Objects/Conversation/Message.php b/src/MessageBird/Objects/Conversation/Message.php
index b687335e..9de3930d 100644
--- a/src/MessageBird/Objects/Conversation/Message.php
+++ b/src/MessageBird/Objects/Conversation/Message.php
@@ -116,7 +116,7 @@ public function loadFromArray($object)
      */
     public function jsonSerialize()
     {
-        $json = array();
+        $json = [];
         
         foreach (get_object_vars($this) as $key => $value) {
             if (!empty($value)) {
diff --git a/src/MessageBird/Objects/Conversation/SendMessage.php b/src/MessageBird/Objects/Conversation/SendMessage.php
index 8a4d2f37..2679a1b6 100644
--- a/src/MessageBird/Objects/Conversation/SendMessage.php
+++ b/src/MessageBird/Objects/Conversation/SendMessage.php
@@ -74,7 +74,7 @@ class SendMessage extends Base implements JsonSerializable
      */
     public function jsonSerialize()
     {
-        $json = array();
+        $json = [];
         
         foreach (get_object_vars($this) as $key => $value) {
             if (!empty($value)) {
diff --git a/src/MessageBird/Objects/Conversation/SendMessageResult.php b/src/MessageBird/Objects/Conversation/SendMessageResult.php
index 27f35baf..e48b71ba 100644
--- a/src/MessageBird/Objects/Conversation/SendMessageResult.php
+++ b/src/MessageBird/Objects/Conversation/SendMessageResult.php
@@ -22,7 +22,7 @@ class SendMessageResult extends Base implements JsonSerializable
      */
     public function jsonSerialize()
     {
-        $json = array();
+        $json = [];
 
         foreach (get_object_vars($this) as $key => $value) {
             if (!empty($value)) {
diff --git a/src/MessageBird/Objects/Conversation/Webhook.php b/src/MessageBird/Objects/Conversation/Webhook.php
index 03486bf3..7271592c 100644
--- a/src/MessageBird/Objects/Conversation/Webhook.php
+++ b/src/MessageBird/Objects/Conversation/Webhook.php
@@ -77,7 +77,7 @@ class Webhook extends Base implements JsonSerializable
      */
     public function jsonSerialize()
     {
-        $json = array();
+        $json = [];
         
         foreach (get_object_vars($this) as $key => $value) {
             if (!empty($value)) {
diff --git a/src/MessageBird/Objects/Group.php b/src/MessageBird/Objects/Group.php
index 468ca356..f702de6a 100644
--- a/src/MessageBird/Objects/Group.php
+++ b/src/MessageBird/Objects/Group.php
@@ -37,7 +37,7 @@ class Group extends Base
      *
      * @var array
      */
-    protected $contacts = array ();
+    protected $contacts =  [];
 
     /**
      * The date and time of the creation of the group in RFC3339 format (Y-m-d\TH:i:sP)
diff --git a/src/MessageBird/Objects/Hlr.php b/src/MessageBird/Objects/Hlr.php
index 9338d030..e7b21a7a 100644
--- a/src/MessageBird/Objects/Hlr.php
+++ b/src/MessageBird/Objects/Hlr.php
@@ -49,7 +49,7 @@ class Hlr extends Base
      *
      * @var array
      */
-    public $details = array();
+    public $details = [];
 
     /**
      * A client reference. Here you can put your own reference,
diff --git a/src/MessageBird/Objects/Message.php b/src/MessageBird/Objects/Message.php
index 8c92e2e3..a3e21a3c 100644
--- a/src/MessageBird/Objects/Message.php
+++ b/src/MessageBird/Objects/Message.php
@@ -95,7 +95,7 @@ class Message extends Base
      *
      * @var array
      */
-    public $typeDetails = array ();
+    public $typeDetails =  [];
 
     /**
      * The datacoding used, can be plain or unicode
@@ -129,7 +129,7 @@ class Message extends Base
      *
      * @var array
      */
-    public $recipients = array ();
+    public $recipients =  [];
 
     /**
      * The URL to send status delivery reports for the message to
diff --git a/src/MessageBird/Objects/MmsMessage.php b/src/MessageBird/Objects/MmsMessage.php
index 98fb0c0b..c0068a09 100644
--- a/src/MessageBird/Objects/MmsMessage.php
+++ b/src/MessageBird/Objects/MmsMessage.php
@@ -47,7 +47,7 @@ class MmsMessage extends Base {
      *
      * @var array
      */
-    public $recipients = array();
+    public $recipients = [];
 
     /**
      * The subject of MMS the message.
@@ -69,7 +69,7 @@ class MmsMessage extends Base {
      *
      * @var array
      */
-    public $mediaUrls = array();
+    public $mediaUrls = [];
 
     /**
      * A client reference.
diff --git a/src/MessageBird/Objects/SignedRequest.php b/src/MessageBird/Objects/SignedRequest.php
index 196edb34..fe1b8fb2 100644
--- a/src/MessageBird/Objects/SignedRequest.php
+++ b/src/MessageBird/Objects/SignedRequest.php
@@ -32,7 +32,7 @@ class SignedRequest extends Base
      *
      * @var array
      */
-    public $queryParameters = array();
+    public $queryParameters = [];
 
     /**
      * The signature passed in the MessageBird-Signature header of the request.
@@ -75,7 +75,7 @@ public static function createFromGlobals()
     public static function create($query, $signature, $requestTimestamp, $body)
     {
         if (is_string($query)) {
-            $queryParameters = array();
+            $queryParameters = [];
             parse_str($query, $queryParameters);
         } else {
             $queryParameters = $query;
diff --git a/src/MessageBird/Objects/Voice/BaseList.php b/src/MessageBird/Objects/Voice/BaseList.php
index 79cacd95..4be90765 100644
--- a/src/MessageBird/Objects/Voice/BaseList.php
+++ b/src/MessageBird/Objects/Voice/BaseList.php
@@ -17,5 +17,5 @@ class BaseList extends Base
     public $currentPage;
     public $perPage;
 
-    public $items = array ();
+    public $items =  [];
 }
diff --git a/src/MessageBird/Objects/VoiceMessage.php b/src/MessageBird/Objects/VoiceMessage.php
index bb72c7ff..a45ede49 100644
--- a/src/MessageBird/Objects/VoiceMessage.php
+++ b/src/MessageBird/Objects/VoiceMessage.php
@@ -107,7 +107,7 @@ class VoiceMessage extends Base
      *
      * @var array
      */
-    public $recipients = array ();
+    public $recipients =  [];
 
     /**
      * The URL to send status delivery reports for the voice message to
diff --git a/src/MessageBird/RequestValidator.php b/src/MessageBird/RequestValidator.php
index 2b287d3e..979a84d0 100644
--- a/src/MessageBird/RequestValidator.php
+++ b/src/MessageBird/RequestValidator.php
@@ -49,7 +49,7 @@ public function verify(SignedRequest $request)
 
     private function buildPayloadFromRequest(SignedRequest $request)
     {
-        $parts = array();
+        $parts = [];
 
         // Add request timestamp
         $parts[] = $request->requestTimestamp;
diff --git a/src/MessageBird/Resources/Base.php b/src/MessageBird/Resources/Base.php
index 708569e8..35ad2ff6 100644
--- a/src/MessageBird/Resources/Base.php
+++ b/src/MessageBird/Resources/Base.php
@@ -84,7 +84,7 @@ public function create($object, $query = null)
         return $this->processRequest($body);
     }
 
-    public function getList($parameters = array ())
+    public function getList($parameters =  [])
     {
         list($status, , $body) = $this->HttpClient->performHttpRequest(Common\HttpClient::REQUEST_GET, $this->resourceName, $parameters);
 
@@ -181,7 +181,7 @@ public function processRequest($body)
     public function update($object, $id)
     {
         $objVars = get_object_vars($object);
-        $body = array();
+        $body = [];
         foreach ($objVars as $key => $value) {
             if (null !== $value) {
                 $body[$key] = $value;
diff --git a/src/MessageBird/Resources/Contacts.php b/src/MessageBird/Resources/Contacts.php
index 0b2ade0e..b8d3fe7e 100644
--- a/src/MessageBird/Resources/Contacts.php
+++ b/src/MessageBird/Resources/Contacts.php
@@ -36,7 +36,7 @@ public function __construct(Common\HttpClient $HttpClient)
     public function update($object, $id)
     {
         $objVars = get_object_vars($object);
-        $body = array();
+        $body = [];
         foreach ($objVars as $key => $value) {
             if (null !== $value) {
                 $body[$key] = $value;
@@ -56,7 +56,7 @@ public function update($object, $id)
      * @param array|null $parameters
      * @return $this ->Object
      */
-    public function getMessages($id, $parameters = array())
+    public function getMessages($id, $parameters = [])
     {
         if (is_null($id)) {
             throw new InvalidArgumentException('No contact id provided.');
@@ -72,7 +72,7 @@ public function getMessages($id, $parameters = array())
      * @param array|null $parameters
      * @return $this ->Object
      */
-    public function getGroups($id, $parameters = array())
+    public function getGroups($id, $parameters = [])
     {
         if (is_null($id)) {
             throw new InvalidArgumentException('No contact id provided.');
diff --git a/src/MessageBird/Resources/Conversation/Conversations.php b/src/MessageBird/Resources/Conversation/Conversations.php
index 950fb926..7ada858e 100644
--- a/src/MessageBird/Resources/Conversation/Conversations.php
+++ b/src/MessageBird/Resources/Conversation/Conversations.php
@@ -67,7 +67,7 @@ private function getStartUrl()
      */
     public function create($contactId, $query = null)
     {
-        $body = json_encode(array('contactId' => $contactId));
+        $body = json_encode(['contactId' => $contactId]);
 
         list(, , $body) = $this->HttpClient->performHttpRequest(
             HttpClient::REQUEST_POST,
@@ -90,7 +90,7 @@ public function create($contactId, $query = null)
     public function update($object, $id)
     {
         $objVars = get_object_vars($object);
-        $body = array();
+        $body = [];
 
         foreach ($objVars as $key => $value) {
             if (null !== $value) {
diff --git a/src/MessageBird/Resources/Conversation/Messages.php b/src/MessageBird/Resources/Conversation/Messages.php
index 2e836209..0ba2617a 100644
--- a/src/MessageBird/Resources/Conversation/Messages.php
+++ b/src/MessageBird/Resources/Conversation/Messages.php
@@ -92,7 +92,7 @@ public function create($conversationId, $object, $query = null)
      * @param string $conversationId
      * @param string[] $parameters
      */
-    public function getList($conversationId, $parameters = array())
+    public function getList($conversationId, $parameters = [])
     {
         list($status, , $body) = $this->httpClient->performHttpRequest(
             HttpClient::REQUEST_GET,
@@ -124,7 +124,7 @@ public function getList($conversationId, $parameters = array())
         return $this->processRequest($body);
     }
 
-    public function read($messageId, $parameters = array()) {
+    public function read($messageId, $parameters = []) {
         list($status, , $body) = $this->httpClient->performHttpRequest(
             HttpClient::REQUEST_GET,
             sprintf(self::MESSAGE_RESOURCE_NAME, $messageId),
diff --git a/src/MessageBird/Resources/Groups.php b/src/MessageBird/Resources/Groups.php
index 00a8fa25..fb75a7a7 100644
--- a/src/MessageBird/Resources/Groups.php
+++ b/src/MessageBird/Resources/Groups.php
@@ -40,7 +40,7 @@ public function __construct(Common\HttpClient $HttpClient)
     public function update($object, $id)
     {
         $objVars = get_object_vars($object);
-        $body = array();
+        $body = [];
         foreach ($objVars as $key => $value) {
             if (null !== $value) {
                 $body[$key] = $value;
@@ -67,7 +67,7 @@ public function update($object, $id)
      *
      * @return mixed
      */
-    public function getContacts($id = null, $parameters = array())
+    public function getContacts($id = null, $parameters = [])
     {
         if (is_null($id)) {
             throw new InvalidArgumentException('No group id provided.');
diff --git a/src/MessageBird/Resources/Lookup.php b/src/MessageBird/Resources/Lookup.php
index f104a311..f2f95239 100644
--- a/src/MessageBird/Resources/Lookup.php
+++ b/src/MessageBird/Resources/Lookup.php
@@ -42,7 +42,7 @@ public function read($phoneNumber = null, $countryCode = null)
         }
         $query = null;
         if ($countryCode !== null) {
-            $query = array("countryCode" => $countryCode);
+            $query = ["countryCode" => $countryCode];
         }
         $ResourceName = $this->resourceName . '/' . $phoneNumber;
         list(, , $body) = $this->HttpClient->performHttpRequest(Common\HttpClient::REQUEST_GET, $ResourceName, $query);
diff --git a/src/MessageBird/Resources/LookupHlr.php b/src/MessageBird/Resources/LookupHlr.php
index 059f0d37..9c682c0e 100644
--- a/src/MessageBird/Resources/LookupHlr.php
+++ b/src/MessageBird/Resources/LookupHlr.php
@@ -43,7 +43,7 @@ public function create($hlr, $countryCode = null)
 
         $query = null;
         if ($countryCode !== null) {
-            $query = array("countryCode" => $countryCode);
+            $query = ["countryCode" => $countryCode];
         }
         $ResourceName = $this->resourceName . '/' . ($hlr->msisdn) . '/hlr' ;
         list(, , $body) = $this->HttpClient->performHttpRequest(Common\HttpClient::REQUEST_POST, $ResourceName, $query, json_encode($hlr));
@@ -68,7 +68,7 @@ public function read($phoneNumber = null, $countryCode = null)
 
         $query = null;
         if ($countryCode !== null) {
-            $query = array("countryCode" => $countryCode);
+            $query = ["countryCode" => $countryCode];
         }
         $ResourceName = $this->resourceName . '/' . $phoneNumber . '/hlr' ;
         list(, , $body) = $this->HttpClient->performHttpRequest(Common\HttpClient::REQUEST_GET, $ResourceName, $query, null);
diff --git a/src/MessageBird/Resources/Verify.php b/src/MessageBird/Resources/Verify.php
index 1e271f17..a4bcb56e 100644
--- a/src/MessageBird/Resources/Verify.php
+++ b/src/MessageBird/Resources/Verify.php
@@ -37,7 +37,7 @@ public function __construct(Common\HttpClient $HttpClient)
     public function verify($id, $token)
     {
         $ResourceName = $this->resourceName . (($id) ? '/' . $id : null);
-        list(, , $body) = $this->HttpClient->performHttpRequest(Common\HttpClient::REQUEST_GET, $ResourceName, array('token' => $token));
+        list(, , $body) = $this->HttpClient->performHttpRequest(Common\HttpClient::REQUEST_GET, $ResourceName, ['token' => $token]);
         return $this->processRequest($body);
     }
 }
diff --git a/src/MessageBird/Resources/Voice/Base.php b/src/MessageBird/Resources/Voice/Base.php
index f092a865..8d6f6109 100644
--- a/src/MessageBird/Resources/Voice/Base.php
+++ b/src/MessageBird/Resources/Voice/Base.php
@@ -13,7 +13,7 @@
  */
 class Base extends \MessageBird\Resources\Base
 {
-    public function getList($parameters = array())
+    public function getList($parameters = [])
     {
         list($status, , $body) = $this->HttpClient->performHttpRequest(
             Common\HttpClient::REQUEST_GET,
diff --git a/src/MessageBird/Resources/Voice/Legs.php b/src/MessageBird/Resources/Voice/Legs.php
index e7eb91dc..8130e9ce 100644
--- a/src/MessageBird/Resources/Voice/Legs.php
+++ b/src/MessageBird/Resources/Voice/Legs.php
@@ -54,7 +54,7 @@ public function getObject()
      *
      * @return Objects\Voice\Leg
      */
-    public function getList($callId, $parameters = array())
+    public function getList($callId, $parameters = [])
     {
         list($status, , $body) = $this->HttpClient->performHttpRequest(
             Common\HttpClient::REQUEST_GET,
diff --git a/src/MessageBird/Resources/Voice/Recordings.php b/src/MessageBird/Resources/Voice/Recordings.php
index cf155241..bdbe8fe7 100644
--- a/src/MessageBird/Resources/Voice/Recordings.php
+++ b/src/MessageBird/Resources/Voice/Recordings.php
@@ -55,7 +55,7 @@ public function getObject()
      *
      * @return Objects\Voice\Recording
      */
-    public function getList($callId, $legId, $parameters = array())
+    public function getList($callId, $legId, $parameters = [])
     {
         list($status, , $body) = $this->HttpClient->performHttpRequest(
             Common\HttpClient::REQUEST_GET,
diff --git a/src/MessageBird/Resources/Voice/Transcriptions.php b/src/MessageBird/Resources/Voice/Transcriptions.php
index d49a4bf3..5bcaa4d3 100644
--- a/src/MessageBird/Resources/Voice/Transcriptions.php
+++ b/src/MessageBird/Resources/Voice/Transcriptions.php
@@ -72,7 +72,7 @@ public function create($callId, $legId, $recordingId)
      *
      * @return Objects\Voice\Transcription
      */
-    public function getList($callId, $legId, $recordingId, $parameters = array())
+    public function getList($callId, $legId, $recordingId, $parameters = [])
     {
         list($status, , $body) = $this->HttpClient->performHttpRequest(
             Common\HttpClient::REQUEST_GET,
diff --git a/tests/integration/BaseTest.php b/tests/integration/BaseTest.php
index 4e51cfce..03840ba6 100644
--- a/tests/integration/BaseTest.php
+++ b/tests/integration/BaseTest.php
@@ -12,7 +12,7 @@ class BaseTest extends TestCase
 
     protected function setUp()
     {
-        $this->mockClient = $this->getMockBuilder("\MessageBird\Common\HttpClient")->setConstructorArgs(array("fake.messagebird.dev"))->getMock();
+        $this->mockClient = $this->getMockBuilder("\MessageBird\Common\HttpClient")->setConstructorArgs(["fake.messagebird.dev"])->getMock();
         $this->client = new \MessageBird\Client('YOUR_ACCESS_KEY', $this->mockClient);
     }
 
diff --git a/tests/integration/HttpClientTest.php b/tests/integration/HttpClientTest.php
index 1d93de30..3e6a262f 100644
--- a/tests/integration/HttpClientTest.php
+++ b/tests/integration/HttpClientTest.php
@@ -12,7 +12,7 @@ public function testHttpClient()
         $url = $client->getRequestUrl('a', null);
         $this->assertSame(Client::ENDPOINT.'/a', $url);
 
-        $url = $client->getRequestUrl('a', array('b' => 1));
+        $url = $client->getRequestUrl('a', ['b' => 1]);
         $this->assertSame(Client::ENDPOINT.'/a?b=1', $url);
     }
 
diff --git a/tests/integration/chat/ChatTest.php b/tests/integration/chat/ChatTest.php
index 219350e5..c4512385 100644
--- a/tests/integration/chat/ChatTest.php
+++ b/tests/integration/chat/ChatTest.php
@@ -14,7 +14,7 @@ public function testCreateChatMessage()
         $ChatMessage->payload = 'This is a test message to test the Chat API';
         $ChatMessage->type = 'text';
 
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(200, '', '{"type":"text","payload":"This is a test message to test the Chat API","contactId":"9d754dac577e3ff103cdf4n29856560"}'));
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([200, '', '{"type":"text","payload":"This is a test message to test the Chat API","contactId":"9d754dac577e3ff103cdf4n29856560"}']);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("POST", 'messages', null, '{"type":"text","payload":"This is a test message to test the Chat API","contactId":"9d754dac577e3ff103cdf4n29856560"}');
         $this->client->chatMessages->create($ChatMessage);
     }
@@ -22,8 +22,8 @@ public function testCreateChatMessage()
     public function testListChatMessage()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'messages', array ('offset' => 100, 'limit' => 30), null);
-        $ChatMessageList = $this->client->chatMessages->getList(array ('offset' => 100, 'limit' => 30));
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'messages',  ['offset' => 100, 'limit' => 30], null);
+        $ChatMessageList = $this->client->chatMessages->getList( ['offset' => 100, 'limit' => 30]);
     }
 
     public function testReadChatMessage()
@@ -41,12 +41,12 @@ public function testCreateChatChannel()
         $ChatChannel->platformId = 'e84f332c5649a5f911e569n69330697';
 
         $ChatChannel->channelDetails =
-            array(
+            [
                 'botName' => 'testBot',
                 'token' => '1234566778:A34JT44Yr4amk234352et5hvRnHeAEHA'
-            );
+            ];
 
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(200, '', '{"name":"Test Channel Telegram","platformId":"e84f332c5649a5f911e569n69330697","channelDetails":{"botName":"testBot","token":"1234566778:A34JT44Yr4amk234352et5hvRnHeAEHA"},"callbackUrl":null}'));
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([200, '', '{"name":"Test Channel Telegram","platformId":"e84f332c5649a5f911e569n69330697","channelDetails":{"botName":"testBot","token":"1234566778:A34JT44Yr4amk234352et5hvRnHeAEHA"},"callbackUrl":null}']);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("POST", 'channels', null, '{"name":"Test Channel Telegram","platformId":"e84f332c5649a5f911e569n69330697","channelDetails":{"botName":"testBot","token":"1234566778:A34JT44Yr4amk234352et5hvRnHeAEHA"},"callbackUrl":null}');
         $this->client->chatChannels->create($ChatChannel);
     }
@@ -54,8 +54,8 @@ public function testCreateChatChannel()
     public function testListChatChannels()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'channels', array ('offset' => 100, 'limit' => 30), null);
-        $ChannelList = $this->client->chatChannels->getList(array ('offset' => 100, 'limit' => 30));
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'channels',  ['offset' => 100, 'limit' => 30], null);
+        $ChannelList = $this->client->chatChannels->getList( ['offset' => 100, 'limit' => 30]);
     }
 
     public function testReadChatChannel()
@@ -78,7 +78,7 @@ public function testUpdateChatChannel()
         $ChatChannel->name = '9d2345ac577e4f103cd3d4529856560';
         $ChatChannel->callbackUrl = 'http://testurl.dev';
 
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(200, '', '{"name":"9d2345ac577e4f103cd3d4529856560","callbackUrl":"http:\/\/testurl.dev"}'));
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([200, '', '{"name":"9d2345ac577e4f103cd3d4529856560","callbackUrl":"http:\/\/testurl.dev"}']);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("PUT", 'channels/234agfgADFH2974gaADFH3hudf9h', null, '{"name":"9d2345ac577e4f103cd3d4529856560","callbackUrl":"http:\/\/testurl.dev"}');
         $this->client->chatChannels->update($ChatChannel,'234agfgADFH2974gaADFH3hudf9h');
     }
@@ -86,8 +86,8 @@ public function testUpdateChatChannel()
     public function testListChatPlatforms()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'platforms', array ('offset' => 100, 'limit' => 30), null);
-        $ChannelList = $this->client->chatPlatforms->getList(array ('offset' => 100, 'limit' => 30));
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'platforms',  ['offset' => 100, 'limit' => 30], null);
+        $ChannelList = $this->client->chatPlatforms->getList( ['offset' => 100, 'limit' => 30]);
     }
 
     public function testReadChatPlatform()
@@ -100,8 +100,8 @@ public function testReadChatPlatform()
     public function testListChatContacts()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'contacts', array ('offset' => 100, 'limit' => 30), null);
-        $ContactList = $this->client->chatContacts->getList(array ('offset' => 100, 'limit' => 30));
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'contacts',  ['offset' => 100, 'limit' => 30], null);
+        $ContactList = $this->client->chatContacts->getList( ['offset' => 100, 'limit' => 30]);
     }
 
     public function testReadChatContact()
diff --git a/tests/integration/contacts/ContactTest.php b/tests/integration/contacts/ContactTest.php
index f3adde86..ff7e56e0 100644
--- a/tests/integration/contacts/ContactTest.php
+++ b/tests/integration/contacts/ContactTest.php
@@ -19,7 +19,7 @@ public function testCreateContact()
         $Contact->custom4 = "Customfield4";
 
 
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->willReturn(array(200, '', '{
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->willReturn([200, '', '{
             "id": "61afc0531573b08ddbe36e1c85602827",
             "href": "https://rest.messagebird.com/contacts/61afc0531573b08ddbe36e1c85602827",
             "msisdn": 31612345678,
@@ -41,15 +41,15 @@ public function testCreateContact()
             },
             "createdDatetime": "2016-04-29T09:42:26+00:00",
             "updatedDatetime": "2016-04-29T09:42:26+00:00"
-        }'));
+        }']);
         $this->client->contacts->create($Contact);
     }
 
     public function testListContacts()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'contacts', array ('offset' => 100, 'limit' => 30), null);
-        $this->client->contacts->getList(array ('offset' => 100, 'limit' => 30));
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'contacts',  ['offset' => 100, 'limit' => 30], null);
+        $this->client->contacts->getList( ['offset' => 100, 'limit' => 30]);
     }
 
     public function testViewContact()
@@ -72,11 +72,11 @@ public function testContactGetGroups()
             ->with(
                 $this->equalTo(MessageBird\Common\HttpClient::REQUEST_GET), $this->equalTo('contacts/contact_id/groups'), $this->anything(), $this->anything()
             )
-            ->willReturn(array(
+            ->willReturn([
                 200,
                 '',
                 '{"offset":0,"limit":20,"count":1,"totalCount":1,"links":{"first":"","previous":null,"next":null,"last":""},"items":[{"id":"contact_id","href":"","name":"GroupName","contacts":{"totalCount":1,"href":""},"createdDatetime":"","updatedDatetime":""}]}'
-            ));
+            ]);
 
         $ResultingGroupList = $this->client->contacts->getGroups("contact_id");
 
@@ -85,25 +85,25 @@ public function testContactGetGroups()
         $GroupList->offset = 0;
         $GroupList->count = 1;
         $GroupList->totalCount = 1;
-        $GroupList->links = (object) array(
+        $GroupList->links = (object) [
             'first' => '',
             'previous' => null,
             'next' => null,
             'last' => ''
-        );
-        $GroupList->items = array(
-            (object) array(
+        ];
+        $GroupList->items = [
+            (object) [
                 'id' => 'contact_id',
                 'href' => '',
                 'name' => 'GroupName',
-                'contacts' => (object) array(
+                'contacts' => (object) [
                     'totalCount' => 1,
                     'href' => ''
-                ),
+                ],
                 'createdDatetime' => '',
                 'updatedDatetime' => ''
-            )
-        );
+            ]
+        ];
 
         $this->assertEquals($GroupList, $ResultingGroupList);
     }
@@ -114,11 +114,11 @@ public function testContactGetMessages()
             ->with(
                 $this->equalTo(MessageBird\Common\HttpClient::REQUEST_GET), $this->equalTo('contacts/contact_id/messages'), $this->anything(), $this->anything()
             )
-            ->willReturn(array(
+            ->willReturn([
                 200,
                 '',
                 '{"offset":0,"limit":20,"count":1,"totalCount":1,"links":{"first":"","previous":null,"next":null,"last":""},"items":[{"id":"contact_id","href":"","direction":"mt","type":"sms","originator":"MsgBird","body":"MessageBody","reference":null,"validity":null,"gateway":0,"typeDetails":{},"datacoding":"plain","mclass":1,"scheduledDatetime":null,"createdDatetime":"","recipients":{"totalCount":1,"totalSentCount":1,"totalDeliveredCount":1,"totalDeliveryFailedCount":0,"items":[{"recipient":12345678912,"status":"delivered","statusDatetime":""}]}}]}'
-            ));
+            ]);
 
         $Messages = $this->client->contacts->getMessages("contact_id");
         foreach($Messages->items as $Message) {
diff --git a/tests/integration/conversation/ConversationContentTest.php b/tests/integration/conversation/ConversationContentTest.php
index bcde5197..a8eb3b1f 100644
--- a/tests/integration/conversation/ConversationContentTest.php
+++ b/tests/integration/conversation/ConversationContentTest.php
@@ -26,7 +26,7 @@ private function messageFromJson($json)
     public function testAudioContent()
     {
         $content = new Content();
-        $content->audio = array('url' => 'https://example.com/audio.mp3');
+        $content->audio = ['url' => 'https://example.com/audio.mp3'];
 
         $message = new Message();
         $message->content = $content;
@@ -40,7 +40,7 @@ public function testAudioContent()
     public function testFileContent()
     {
         $content = new Content();
-        $content->file = array('url' => 'https://example.com/file.pdf');
+        $content->file = ['url' => 'https://example.com/file.pdf'];
 
         $message = new Message();
         $message->content = $content;
@@ -54,7 +54,7 @@ public function testFileContent()
     public function testImageContent()
     {
         $content = new Content();
-        $content->image = array('url' => 'https://example.com/image.png');
+        $content->image = ['url' => 'https://example.com/image.png'];
 
         $message = new Message();
         $message->content = $content;
@@ -68,10 +68,10 @@ public function testImageContent()
     public function testLocationContent()
     {
         $content = new Content();
-        $content->location = array(
+        $content->location = [
             'latitude' => '37.778326',
             'longitude' => '-122.394648',
-        );
+        ];
 
         $message = new Message();
         $message->content = $content;
@@ -99,7 +99,7 @@ public function testTextContent()
     public function testVideoContent()
     {
         $content = new Content();
-        $content->video = array('url' => 'https://example.com/video.mp4');
+        $content->video = ['url' => 'https://example.com/video.mp4'];
 
         $message = new Message();
         $message->content = $content;
diff --git a/tests/integration/conversation/ConversationMessageTest.php b/tests/integration/conversation/ConversationMessageTest.php
index 87111a53..3c342c17 100644
--- a/tests/integration/conversation/ConversationMessageTest.php
+++ b/tests/integration/conversation/ConversationMessageTest.php
@@ -58,12 +58,12 @@ public function testCreateImage()
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
             ->with('POST', 'conversations/some-conversation-id/messages', null, '{"channelId":"abcd1234","type":"image","content":{"image":{"url":"https:\/\/developers.messagebird.com\/assets\/images\/glyph.svg"}}}')
-            ->willReturn(array(200, '', '{}'));
+            ->willReturn([200, '', '{}']);
 
         $content = new Content();
-        $content->image = array(
+        $content->image = [
             'url' => 'https://developers.messagebird.com/assets/images/glyph.svg'
-        );
+        ];
 
         $message = new Message();
         $message->channelId = 'abcd1234';
@@ -78,13 +78,13 @@ public function testCreateLocation()
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
             ->with('POST', 'conversations/some-contact-id/messages', null, '{"channelId":"abcd1234","type":"location","content":{"location":{"latitude":"52.379112","longitude":"4.900384"}}}')
-            ->willReturn(array(200, '', '{}'));
+            ->willReturn([200, '', '{}']);
 
         $content = new Content();
-        $content->location = array(
+        $content->location = [
             'latitude' => '52.379112',
             'longitude' => '4.900384'
-        );
+        ];
 
         $message = new Message();
         $message->channelId = 'abcd1234';
@@ -99,7 +99,7 @@ public function testCreateText()
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
             ->with('POST', 'conversations/some-other-contact-id/messages', null, '{"channelId":"abcd1234","type":"text","content":{"text":"Hello world"}}')
-            ->willReturn(array(200, '', '{}'));
+            ->willReturn([200, '', '{}']);
 
         $content = new Content();
         $content->text = 'Hello world';
@@ -117,7 +117,7 @@ public function testCreateWithoutChannel()
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
             ->with('POST', 'conversations/genid/messages', null, '{"type":"text","content":{"text":"Hello world"}}')
-            ->willReturn(array(200, '', '{}'));
+            ->willReturn([200, '', '{}']);
 
         $content = new Content();
         $content->text = 'Hello world';
@@ -133,8 +133,8 @@ public function testListPagination()
     {
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
-            ->with('GET', 'conversations/genid/messages', array(), null)
-            ->willReturn(array(200, '', self::LIST_RESPONSE));
+            ->with('GET', 'conversations/genid/messages', [], null)
+            ->willReturn([200, '', self::LIST_RESPONSE]);
 
         $messages = $this->client->conversationMessages->getList('genid');
 
@@ -148,15 +148,15 @@ public function testListObject()
     {
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
-            ->with('GET', 'conversations/genid/messages', array(), null)
-            ->willReturn(array(200, '', self::LIST_RESPONSE));
+            ->with('GET', 'conversations/genid/messages', [], null)
+            ->willReturn([200, '', self::LIST_RESPONSE]);
 
         $message = $this->client->conversationMessages->getList('genid')->items[0];
 
         $expectedContent = new Content();
-        $expectedContent->video = array(
+        $expectedContent->video = [
             'url' => 'https://developers.messagebird.com/assets/videos/foo.mp4'
-        );
+        ];
 
         $expectedMessage = new Message();
         $expectedMessage->id = 'genid';
@@ -175,16 +175,16 @@ public function testReadMessage()
     {
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
-            ->with('GET', 'messages/message-id', array(), null)
-            ->willReturn(array(200, '', self::READ_RESPONSE));
+            ->with('GET', 'messages/message-id', [], null)
+            ->willReturn([200, '', self::READ_RESPONSE]);
 
 
         $message = $this->client->conversationMessages->read('message-id');
 
         $expectedContent = new Content();
-        $expectedContent->video = array(
+        $expectedContent->video = [
             'url' => 'https://developers.messagebird.com/assets/videos/foo.mp4'
-        );
+        ];
         $expectedMessage = new Message();
         $expectedMessage->id = 'genid';
         $expectedMessage->channelId = 'chid';
diff --git a/tests/integration/conversation/ConversationTest.php b/tests/integration/conversation/ConversationTest.php
index 94938dd8..6f808902 100644
--- a/tests/integration/conversation/ConversationTest.php
+++ b/tests/integration/conversation/ConversationTest.php
@@ -106,13 +106,13 @@ public function testStart()
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
             ->with('POST', 'conversations/start', null, self::START_REQUEST)
-            ->willReturn(array(200, '', '{}'));
+            ->willReturn([200, '', '{}']);
 
         $content = new Content();
-        $content->location = array(
+        $content->location = [
             'latitude' => '37.778326',
             'longitude' => '-122.394648',
-        );
+        ];
 
         $message = new Message();
         $message->channelId = 'channel-id';
@@ -131,7 +131,7 @@ public function testCreate()
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
             ->with('POST', 'conversations', null, self::CREATE_REQUEST)
-            ->willReturn(array(200, '', '{}'));
+            ->willReturn([200, '', '{}']);
         
         $this->client->conversations->create('some-contact-id');
     }
@@ -140,15 +140,15 @@ public function testList()
     {
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
-            ->with('GET', 'conversations', array(), null)
-            ->willReturn(array(200, '', self::LIST_RESPONSE));
+            ->with('GET', 'conversations', [], null)
+            ->willReturn([200, '', self::LIST_RESPONSE]);
 
         $list = new BaseList();
         $list->limit = 10;
         $list->offset = 0;
         $list->count = 1;
         $list->totalCount = 1;
-        $list->items = array($this->getConversation());
+        $list->items = [$this->getConversation()];
 
         $this->assertEquals(
             $list,
@@ -161,7 +161,7 @@ public function testRead()
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
             ->with('GET', 'conversations/conversation-id', null, null)
-            ->willReturn(array(200, '', self::READ_RESPONSE));
+            ->willReturn([200, '', self::READ_RESPONSE]);
 
         $this->assertEquals(
             $this->getConversation(),
@@ -174,10 +174,10 @@ public function testUpdate()
         $this->mockClient
             ->expects($this->exactly(2))->method('performHttpRequest')
             ->withConsecutive(
-                array('PATCH', 'conversations/conversation-id', null, '{"status":"archived"}'),
-                array('PATCH', 'conversations/conversation-id', null, '{"status":"active"}')                
+                ['PATCH', 'conversations/conversation-id', null, '{"status":"archived"}'],
+                ['PATCH', 'conversations/conversation-id', null, '{"status":"active"}']                
             )
-            ->willReturn(array(200, '', '{}'));
+            ->willReturn([200, '', '{}']);
 
         $conversation = new Conversation();
         
@@ -201,9 +201,9 @@ private function getConversation()
         $contact->msisdn = '31612345678';
         $contact->firstName = 'Foo';
         $contact->lastName = 'Bar';
-        $contact->customDetails = array(
+        $contact->customDetails = [
             'custom1' => 'Baz',
-        );
+        ];
         $contact->createdDatetime = '2018-07-20T12:13:41+00:00';
         $contact->updatedDatetime = '2018-07-20T12:13:51+00:00';
 
@@ -221,7 +221,7 @@ private function getConversation()
 
         $conversation = new Conversation();
         $conversation->contact = $contact;
-        $conversation->channels = array($channel);
+        $conversation->channels = [$channel];
         $conversation->id = 'conversation-id';
         $conversation->href = 'https://conversations.messagebird.com/v1/conversations/conversation-id';
         $conversation->messages = $messages;
diff --git a/tests/integration/conversation/ConversationWebhookTest.php b/tests/integration/conversation/ConversationWebhookTest.php
index 3cae2ec5..6c6de7a9 100644
--- a/tests/integration/conversation/ConversationWebhookTest.php
+++ b/tests/integration/conversation/ConversationWebhookTest.php
@@ -49,7 +49,7 @@ public function testDelete()
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
             ->with('DELETE', 'webhooks/some-id', null, null)
-            ->willReturn(array(204, '', null));
+            ->willReturn([204, '', null]);
 
         $this->client->conversationWebhooks->delete('some-id');
     }
@@ -59,15 +59,15 @@ public function testCreate()
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
             ->with('POST', 'webhooks', null, '{"channelId":"chid","events":["conversation.created","message.created"],"url":"https:\/\/messagebird.com\/webhook-receiver"}')
-            ->willReturn(array(200, '', '{}'));
+            ->willReturn([200, '', '{}']);
 
         $webhook = new Webhook();
         $webhook->channelId = 'chid';
         $webhook->url = 'https://messagebird.com/webhook-receiver';
-        $webhook->events = array(
+        $webhook->events = [
             Webhook::EVENT_CONVERSATION_CREATED,
             Webhook::EVENT_MESSAGE_CREATED,
-        );
+        ];
 
         $this->client->conversationWebhooks->create($webhook);
     }
@@ -76,8 +76,8 @@ public function testListPagination()
     {
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
-            ->with('GET', 'webhooks', array(), null)
-            ->willReturn(array(200, '', self::LIST_RESPONSE));
+            ->with('GET', 'webhooks', [], null)
+            ->willReturn([200, '', self::LIST_RESPONSE]);
 
         $webhooks = $this->client->conversationWebhooks->getList();
 
@@ -91,13 +91,13 @@ public function testListObject()
     {
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
-            ->with('GET', 'webhooks', array(), null)
-            ->willReturn(array(200, '', self::LIST_RESPONSE));
+            ->with('GET', 'webhooks', [], null)
+            ->willReturn([200, '', self::LIST_RESPONSE]);
 
         $expectedWebhook = new Webhook();
         $expectedWebhook->id = 'some-id';
         $expectedWebhook->channelId = 'chid';
-        $expectedWebhook->events = array('conversation.created', 'message.created');
+        $expectedWebhook->events = ['conversation.created', 'message.created'];
         $expectedWebhook->url = 'https://example.com/webhook';
         $expectedWebhook->createdDatetime = '2018-07-31T12:12:43Z';
 
@@ -112,17 +112,17 @@ public function testRead()
         $this->mockClient
             ->expects($this->once())->method('performHttpRequest')
             ->with('GET', 'webhooks/some-id', null, null)
-            ->willReturn(array(200, '', self::READ_RESPONSE));
+            ->willReturn([200, '', self::READ_RESPONSE]);
 
         $webhook = new Webhook();
         $webhook->id = 'some-id';
         $webhook->href = 'https://conversations.messagebird.com/v1/webhooks/some-id';
         $webhook->channelId = 'chid';
         $webhook->url = 'https://messagebird.com/webhook-receiver';
-        $webhook->events = array(
+        $webhook->events = [
             Webhook::EVENT_CONVERSATION_UPDATED,
             Webhook::EVENT_MESSAGE_UPDATED,
-        );
+        ];
         $webhook->createdDatetime = '2018-07-20T12:13:41+00:00';
         $webhook->updatedDatetime = '2018-07-20T12:13:51+00:00';
 
diff --git a/tests/integration/groups/GroupTest.php b/tests/integration/groups/GroupTest.php
index 42a28beb..77a6ce72 100644
--- a/tests/integration/groups/GroupTest.php
+++ b/tests/integration/groups/GroupTest.php
@@ -13,7 +13,7 @@ public function testCreateGroup()
         $Group->name  = "Home";
 
 
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->willReturn(array(200, '', '{
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->willReturn([200, '', '{
             "id": "61afc0531573b08ddbe36e1c85602827",
             "href": "https://rest.messagebird.com/groups/61afc0531573b08ddbe36e1c85602827",
             "name": "Home",
@@ -23,15 +23,15 @@ public function testCreateGroup()
             },
             "createdDatetime": "2016-04-29T09:42:26+00:00",
             "updatedDatetime": "2016-04-29T09:42:26+00:00"
-        }'));
+        }']);
         $this->client->groups->create($Group);
     }
 
     public function testListGroups()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'groups', array ('offset' => 100, 'limit' => 30), null);
-        $this->client->groups->getList(array ('offset' => 100, 'limit' => 30));
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'groups',  ['offset' => 100, 'limit' => 30], null);
+        $this->client->groups->getList( ['offset' => 100, 'limit' => 30]);
     }
 
     public function testViewGroup()
diff --git a/tests/integration/lookup/LookupTest.php b/tests/integration/lookup/LookupTest.php
index 0533d1ee..7d6166dd 100644
--- a/tests/integration/lookup/LookupTest.php
+++ b/tests/integration/lookup/LookupTest.php
@@ -23,7 +23,7 @@ public function testReadLookupWithEmptyNumber()
     public function testReadLookupWithCountryCode()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $params = array("countryCode" => "NL");
+        $params = ["countryCode" => "NL"];
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'lookup/612345678', $params, null);
         $this->client->lookup->read(612345678, $params["countryCode"]);
     }
@@ -55,7 +55,7 @@ public function testCreateLookupHlrWithCountryCode()
         $Hlr->msisdn     = 612345678;
         $Hlr->reference  = "CoolReference";
 
-        $params = array("countryCode" => "NL");
+        $params = ["countryCode" => "NL"];
 
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("POST", 'lookup/'.$Hlr->msisdn.'/hlr', $params, json_encode($Hlr));
 
@@ -78,7 +78,7 @@ public function testReadLookupHlrWithEmptyNumber()
     public function testReadLookupHlrWithCountryCode()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $params = array("countryCode" => "NL");
+        $params = ["countryCode" => "NL"];
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'lookup/612345678/hlr', $params, null);
         $this->client->lookupHlr->read(612345678, $params["countryCode"]);
     }
diff --git a/tests/integration/messages/MessagesTest.php b/tests/integration/messages/MessagesTest.php
index 9e246bf1..429c6735 100644
--- a/tests/integration/messages/MessagesTest.php
+++ b/tests/integration/messages/MessagesTest.php
@@ -11,10 +11,10 @@ public function testCreateMessage()
     {
         $Message             = new \MessageBird\Objects\Message();
         $Message->originator = 'MessageBird';
-        $Message->recipients = array(31612345678);
+        $Message->recipients = [31612345678];
         $Message->body       = 'This is a test message.';
 
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(200, '', '{
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([200, '', '{
                   "id":"e8077d803532c0b5937c639b60216938",
                   "href":"https://rest.messagebird.com/messages/e8077d803532c0b5937c639b60216938",
                   "direction":"mt",
@@ -45,7 +45,7 @@ public function testCreateMessage()
                     ]
                   },
                   "reportUrl":null
-                }'));
+                }']);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("POST", 'messages', null, '{"direction":"mt","type":"sms","originator":"MessageBird","body":"This is a test message.","reference":null,"validity":null,"gateway":null,"typeDetails":[],"datacoding":"plain","mclass":1,"scheduledDatetime":null,"recipients":[31612345678],"reportUrl":null}');
         $this->client->messages->create($Message);
     }
@@ -55,7 +55,7 @@ public function testPremiumSmsMessage()
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
         $Message             = new \MessageBird\Objects\Message();
         $Message->originator = 'MessageBird';
-        $Message->recipients = array(31612345678);
+        $Message->recipients = [31612345678];
         $Message->body       = 'This is a test message.';
         $Message->setPremiumSms(2002, 'mb', 1, 2);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("POST", 'messages', null, '{"direction":"mt","type":"premium","originator":"MessageBird","body":"This is a test message.","reference":null,"validity":null,"gateway":null,"typeDetails":{"shortcode":2002,"keyword":"mb","tariff":1,"mid":2},"datacoding":"plain","mclass":1,"scheduledDatetime":null,"recipients":[31612345678],"reportUrl":null}');
@@ -67,7 +67,7 @@ public function testBinarySmsMessage()
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
         $Message             = new \MessageBird\Objects\Message();
         $Message->originator = 'MessageBird';
-        $Message->recipients = array(31612345678);
+        $Message->recipients = [31612345678];
         $Message->body       = 'This is a test message.';
         $Message->setBinarySms("HEADER", "test");
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("POST", 'messages', null, '{"direction":"mt","type":"binary","originator":"MessageBird","body":"test","reference":null,"validity":null,"gateway":null,"typeDetails":{"udh":"HEADER"},"datacoding":"plain","mclass":1,"scheduledDatetime":null,"recipients":[31612345678],"reportUrl":null}');
@@ -80,7 +80,7 @@ public function testFlashSmsMessage()
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
         $Message             = new \MessageBird\Objects\Message();
         $Message->originator = 'MessageBird';
-        $Message->recipients = array(31612345678);
+        $Message->recipients = [31612345678];
         $Message->body       = 'This is a test message.';
         $Message->setBinarySms("HEADER", "test");
         $Message->setFlash(true);
@@ -92,8 +92,8 @@ public function testFlashSmsMessage()
     public function testListMessage()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'messages', array ('offset' => 100, 'limit' => 30), null);
-        $this->client->messages->getList(array ('offset' => 100, 'limit' => 30));
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'messages',  ['offset' => 100, 'limit' => 30], null);
+        $this->client->messages->getList( ['offset' => 100, 'limit' => 30]);
     }
 
     public function testReadMessage()
diff --git a/tests/integration/mms/MmsTest.php b/tests/integration/mms/MmsTest.php
index 3482457a..1c7c2333 100644
--- a/tests/integration/mms/MmsTest.php
+++ b/tests/integration/mms/MmsTest.php
@@ -9,7 +9,7 @@ public function testCreateMmsFail()
         $this->mockClient->expects($this->once())
             ->method('performHttpRequest')
             ->with('POST', 'mms', null, json_encode($MmsMessage))
-            ->willReturn(array(422, '', '{"errors":[{"code":9,"description":"no (correct) recipients found","parameter":"recipients"}]}'));
+            ->willReturn([422, '', '{"errors":[{"code":9,"description":"no (correct) recipients found","parameter":"recipients"}]}']);
 
         $this->client->mmsMessages->create($MmsMessage);
     }
@@ -22,7 +22,7 @@ public function testCreateMmsSuccess()
         $this->mockClient->expects($this->once())
             ->method('performHttpRequest')
             ->with('POST', 'mms', null, json_encode($MmsMessage))
-            ->willReturn(array(200, '', $this->generateMmsServerResponse($MmsMessage, $dummyMessageId)));
+            ->willReturn([200, '', $this->generateMmsServerResponse($MmsMessage, $dummyMessageId)]);
 
         $ResultMmsMessage = $this->client->mmsMessages->create($MmsMessage);
 
@@ -35,8 +35,8 @@ public function testListMms()
 
         $this->mockClient->expects($this->once())
             ->method('performHttpRequest')
-            ->with('GET', 'mms', array('offset' => '100', 'limit' => '30'), null)
-            ->willReturn(array(200, '',
+            ->with('GET', 'mms', ['offset' => '100', 'limit' => '30'], null)
+            ->willReturn([200, '',
                 '{ 
                     "offset": 0, "limit": 20, "count": 1, "totalCount": 2,
                     "links": {
@@ -48,9 +48,9 @@ public function testListMms()
                     "items": [ ' . $this->generateMmsServerResponse($dummyMessage, 'message_id') . ',
                                ' . $this->generateMmsServerResponse($dummyMessage, 'message_id_2') . ']
                 }'
-            ));
+            ]);
 
-        $ResultMessages = $this->client->mmsMessages->getList(array('offset' => 100, 'limit' => 30));
+        $ResultMessages = $this->client->mmsMessages->getList(['offset' => 100, 'limit' => 30]);
 
         $this->assertAttributeEquals(0, 'offset', $ResultMessages);
         $this->assertAttributeEquals(1, 'count', $ResultMessages);
@@ -69,8 +69,8 @@ public function testDeleteMms()
             ->method('performHttpRequest')
             ->with('DELETE', 'mms/message_id', null, null)
             ->will($this->onConsecutiveCalls(
-                array(204, '', ''),
-                array(404, '', '{"errors":[{"code":20,"description":"message not found","parameter":null}]}')
+                [204, '', ''],
+                [404, '', '{"errors":[{"code":20,"description":"message not found","parameter":null}]}']
             ));
 
         $this->client->mmsMessages->delete('message_id');
@@ -88,8 +88,8 @@ public function testReadMms()
             ->method('performHttpRequest')
             ->with('GET', $this->logicalOr('mms/message_id', 'mms/unknown_message_id'), null, null)
             ->will($this->onConsecutiveCalls(
-                array('200', '', $this->generateMmsServerResponse($dummyMessage, 'message_id')),
-                array('404', '', '{"errors":[{"code":20,"description":"message not found","parameter":null}]}')
+                ['200', '', $this->generateMmsServerResponse($dummyMessage, 'message_id')],
+                ['404', '', '{"errors":[{"code":20,"description":"message not found","parameter":null}]}']
             ));
 
         $ResultMmsMessage = $this->client->mmsMessages->read('message_id');
@@ -107,9 +107,9 @@ private function generateDummyMessage()
         $MmsMessage = new \MessageBird\Objects\MmsMessage();
         $MmsMessage->originator = "MessageBird";
         $MmsMessage->direction = 'ot';
-        $MmsMessage->recipients = array(31621938645);
+        $MmsMessage->recipients = [31621938645];
         $MmsMessage->body = 'Have you seen this logo?';
-        $MmsMessage->mediaUrls = array('https://www.messagebird.com/assets/images/og/messagebird.gif');
+        $MmsMessage->mediaUrls = ['https://www.messagebird.com/assets/images/og/messagebird.gif'];
         return $MmsMessage;
     }
 
@@ -131,7 +131,7 @@ private function assertMessagesAreEqual(\MessageBird\Objects\MmsMessage $MmsMess
         $this->assertAttributeEquals($MmsMessage->reference, 'reference', $ResultMmsMessage);
 
         foreach($ResultMmsMessage->recipients->items as $item) {
-            $this->assertArraySubset(array($item->recipient), $MmsMessage->recipients);
+            $this->assertArraySubset([$item->recipient], $MmsMessage->recipients);
         }
     }
 
diff --git a/tests/integration/numbers/AvailablePhoneNumbersTest.php b/tests/integration/numbers/AvailablePhoneNumbersTest.php
index 9f64dc0d..545fae6e 100644
--- a/tests/integration/numbers/AvailablePhoneNumbersTest.php
+++ b/tests/integration/numbers/AvailablePhoneNumbersTest.php
@@ -10,7 +10,7 @@ protected function setUp()
     public function testListAvailablePhoneNumbers()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with('GET', 'available-phone-numbers/nl', array (), null);
-        $this->client->availablePhoneNumbers->getList("nl", array());
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with('GET', 'available-phone-numbers/nl',  [], null);
+        $this->client->availablePhoneNumbers->getList("nl", []);
     }
 }
diff --git a/tests/integration/numbers/PhoneNumbersTest.php b/tests/integration/numbers/PhoneNumbersTest.php
index da95cdd1..701b05c7 100644
--- a/tests/integration/numbers/PhoneNumbersTest.php
+++ b/tests/integration/numbers/PhoneNumbersTest.php
@@ -17,16 +17,16 @@ public function testReadPhoneNumber()
     public function testListPhoneNumbers()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with('GET', 'phone-numbers', array (), null);
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with('GET', 'phone-numbers',  [], null);
         $this->client->phoneNumbers->getList();
     }
 
     public function testUpdatePhoneNumber()
     {
         $Number = new \MessageBird\Objects\Number();
-        $Number->tags = array('tag1');
+        $Number->tags = ['tag1'];
 
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(200, '', '{"tags":["tag1"]}'));
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([200, '', '{"tags":["tag1"]}']);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with('PATCH', 'phone-numbers/31612345678', null, '{"tags":["tag1"]}');
         $this->client->phoneNumbers->update($Number, '31612345678');
     }
@@ -40,14 +40,14 @@ public function testPurchasePhoneNumber()
 
         $NumberJSON = '{"number":"31612345678","countryCode":"NL","billingIntervalMonths":1}';
 
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(201, '', "[$NumberJSON]"));
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([201, '', "[$NumberJSON]"]);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with('POST', 'phone-numbers', null, $NumberJSON);
         $this->client->phoneNumbers->create($NumberPurchaseRequest);
     }
 
     public function testCancelPhoneNumber()
     {
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(204, '', ''));
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([204, '', '']);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with('DELETE', 'phone-numbers/31612345678', null, null);
         $this->client->phoneNumbers->delete('31612345678');
     }
diff --git a/tests/integration/verify/VerifyTest.php b/tests/integration/verify/VerifyTest.php
index c796a968..008b45bc 100644
--- a/tests/integration/verify/VerifyTest.php
+++ b/tests/integration/verify/VerifyTest.php
@@ -26,7 +26,7 @@ public function testVerifyOtp()
         $Verify->recipient = 31612345678;
         $Verify->reference = 'Yoloswag3000';
 
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'verify/onofao3f82f7u2fb2uf', array('token' => '123456'));
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'verify/onofao3f82f7u2fb2uf', ['token' => '123456']);
 
         $this->client->verify->verify('onofao3f82f7u2fb2uf', 123456);
     }
diff --git a/tests/integration/voice/VoiceTest.php b/tests/integration/voice/VoiceTest.php
index 831e1105..51ef7ee2 100644
--- a/tests/integration/voice/VoiceTest.php
+++ b/tests/integration/voice/VoiceTest.php
@@ -14,11 +14,11 @@ protected function setUp()
     public function testListVoiceCall()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'calls', array(
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'calls', [
             'offset' => 100,
             'limit' => 30,
-        ), null);
-        $this->client->voiceCalls->getList(array('offset' => 100, 'limit' => 30));
+        ], null);
+        $this->client->voiceCalls->getList(['offset' => 100, 'limit' => 30]);
     }
 
     public function testReadVoiceCall()
@@ -33,16 +33,16 @@ public function testCreateVoiceCall()
         $voiceCall = new \MessageBird\Objects\Voice\Call();
         $voiceCall->source = '31612354678';
         $voiceCall->destination = '31611223344';
-        $voiceCall->callFlow = array(
+        $voiceCall->callFlow = [
             'title' => 'Foobar',
-            'steps' => array(
-                array(
+            'steps' => [
+                [
                     'action' => 'hangup',
-                ),
-            ),
-        );
+                ],
+            ],
+        ];
 
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(201, '', '{
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([201, '', '{
   "data": [
     {
       "id": "21025ed1-cc1d-4554-ac05-043fa6c84e00",
@@ -57,7 +57,7 @@ public function testCreateVoiceCall()
   "_links": {
     "self": "/calls/21025ed1-cc1d-4554-ac05-043fa6c84e00"
   }
-}'));
+}']);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("POST", 'calls', null, '{"source":"31612354678","destination":"31611223344","callFlow":{"title":"Foobar","steps":[{"action":"hangup"}]}}');
         $this->client->voiceCalls->create($voiceCall);
     }
@@ -65,11 +65,11 @@ public function testCreateVoiceCall()
     public function testListVoiceLegs()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'calls/foobar/legs', array(
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'calls/foobar/legs', [
             'offset' => 100,
             'limit' => 30,
-        ), null);
-        $this->client->voiceLegs->getList('foobar', array('offset' => 100, 'limit' => 30));
+        ], null);
+        $this->client->voiceLegs->getList('foobar', ['offset' => 100, 'limit' => 30]);
     }
 
     public function testReadVoiceLeg()
@@ -82,11 +82,11 @@ public function testReadVoiceLeg()
     public function testListVoiceRecordings()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'calls/foo/legs/bar/recordings', array(
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'calls/foo/legs/bar/recordings', [
             'offset' => 100,
             'limit' => 30,
-        ), null);
-        $this->client->voiceRecordings->getList('foo', 'bar', array('offset' => 100, 'limit' => 30));
+        ], null);
+        $this->client->voiceRecordings->getList('foo', 'bar', ['offset' => 100, 'limit' => 30]);
     }
 
     public function testReadVoiceRecording()
@@ -99,7 +99,7 @@ public function testReadVoiceRecording()
     public function testDeleteVoiceRecording()
     {
        $this->expectException(\MessageBird\Exceptions\ServerException::class);
-       $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(204, '', null));
+       $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([204, '', null]);
        $this->client->voiceRecordings->delete('foo','bar','baz');
     }
 
@@ -113,7 +113,7 @@ public function testDownloadVoiceRecording()
 
     public function testCreateVoiceTranscription()
     {
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(201, '', '{
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([201, '', '{
   "data": [
      {
        "id": "87c377ce-1629-48b6-ad01-4b4fd069c53c",
@@ -127,7 +127,7 @@ public function testCreateVoiceTranscription()
        }
      }
   ]
-}'));
+}']);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("POST", 'calls/foo/legs/bar/recordings/baz/transcriptions', null, null);
         $this->client->voiceTranscriptions->create('foo', 'bar', 'baz');
     }
@@ -135,11 +135,11 @@ public function testCreateVoiceTranscription()
     public function testListVoiceTranscriptions()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'calls/foo/legs/bar/recordings/baz/transcriptions', array(
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'calls/foo/legs/bar/recordings/baz/transcriptions', [
             'offset' => 100,
             'limit' => 30,
-        ), null);
-        $this->client->voiceTranscriptions->getList('foo', 'bar', 'baz', array('offset' => 100, 'limit' => 30));
+        ], null);
+        $this->client->voiceTranscriptions->getList('foo', 'bar', 'baz', ['offset' => 100, 'limit' => 30]);
     }
 
     public function testReadVoiceTranscription()
@@ -159,11 +159,11 @@ public function testDownloadVoiceTranscription()
     public function testListVoiceWebhooks()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'webhooks', array(
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'webhooks', [
             'offset' => 100,
             'limit' => 30,
-        ), null);
-        $this->client->voiceWebhooks->getList(array('offset' => 100, 'limit' => 30));
+        ], null);
+        $this->client->voiceWebhooks->getList(['offset' => 100, 'limit' => 30]);
     }
 
     public function testReadVoiceWebhook()
@@ -179,7 +179,7 @@ public function testCreateVoiceWebhook()
         $webhook->url = 'https://example.com/';
         $webhook->token = 'foobar';
 
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(201, '', '{
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([201, '', '{
   "data": [
     {
       "id": "534e1848-235f-482d-983d-e3e11a04f58a",
@@ -201,7 +201,7 @@ public function testCreateVoiceWebhook()
     "currentPage": 1,
     "perPage": 10
   }
-}'));
+}']);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("POST", 'webhooks', null, '{"url":"https:\/\/example.com\/","token":"foobar"}');
         $this->client->voiceWebhooks->create($webhook);
     }
@@ -212,7 +212,7 @@ public function testUpdateVoiceWebhook()
         $webhook->url = 'https://example.com/foo';
         $webhook->token = 'foobar';
 
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(200, '', '{
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([200, '', '{
   "data": [
     {
       "id": "foobar123",
@@ -225,14 +225,14 @@ public function testUpdateVoiceWebhook()
   "_links": {
     "self": "/webhooks/534e1848-235f-482d-983d-e3e11a04f58a"
   }
-}'));
+}']);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("PUT", 'webhooks/foobar123', null, '{"url":"https:\/\/example.com\/foo","token":"foobar"}');
         $this->client->voiceWebhooks->update($webhook, 'foobar123');
     }
 
     public function testDeleteVoiceWebhook()
     {
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(204, '', null));
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([204, '', null]);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("DELETE", 'webhooks/foobar123', null, '');
         $this->client->voiceWebhooks->delete('foobar123');
     }
@@ -241,11 +241,11 @@ public function testDeleteVoiceWebhook()
     public function testListVoiceCallFlows()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'call-flows', array(
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'call-flows', [
             'offset' => 100,
             'limit' => 30,
-        ), null);
-        $this->client->voiceCallFlows->getList(array('offset' => 100, 'limit' => 30));
+        ], null);
+        $this->client->voiceCallFlows->getList(['offset' => 100, 'limit' => 30]);
     }
 
     public function testReadVoiceCallFlow()
@@ -259,16 +259,16 @@ public function testCreateVoiceCallFlow()
     {
         $callFlow = new \MessageBird\Objects\Voice\CallFlow();
         $callFlow->title = 'Foobar';
-        $callFlow->steps = array(
-           array(
+        $callFlow->steps = [
+           [
                'action' => 'transfer',
-               'options' => array(
+               'options' => [
                    'destination' => '31612345678',
-               ),
-           ) ,
-        );
+               ],
+           ] ,
+        ];
 
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(201, '', '{
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([201, '', '{
   "data": [
     {
       "id": "de3ed163-d5fc-45f4-b8c4-7eea7458c635",
@@ -298,7 +298,7 @@ public function testCreateVoiceCallFlow()
     "currentPage": 1,
     "perPage": 10
   }
-}'));
+}']);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("POST", 'call-flows', null, '{"title":"Foobar","steps":[{"action":"transfer","options":{"destination":"31612345678"}}]}');
         $this->client->voiceCallFlows->create($callFlow);
     }
@@ -308,7 +308,7 @@ public function testUpdateVoiceCallFlow()
         $webhook = new \MessageBird\Objects\Voice\Webhook();
         $webhook->title = 'Updated call flow';
 
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(200, '', '{
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([200, '', '{
   "data": [
     {
       "id": "de3ed163-d5fc-45f4-b8c4-7eea7458c635",
@@ -329,14 +329,14 @@ public function testUpdateVoiceCallFlow()
   "_links": {
     "self": "/call-flows/de3ed163-d5fc-45f4-b8c4-7eea7458c635"
   }
-}'));
+}']);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("PUT", 'call-flows/foobar123', null, '{"title":"Updated call flow"}');
         $this->client->voiceCallFlows->update($webhook, 'foobar123');
     }
 
     public function testDeleteVoiceCallFlow()
     {
-        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn(array(204, '', null));
+        $this->mockClient->expects($this->atLeastOnce())->method('performHttpRequest')->willReturn([204, '', null]);
         $this->mockClient->expects($this->once())->method('performHttpRequest')->with("DELETE", 'call-flows/foobar123', null, '');
         $this->client->voiceCallFlows->delete('foobar123');
     }
diff --git a/tests/integration/voicemessages/VoiceMessagesTest.php b/tests/integration/voicemessages/VoiceMessagesTest.php
index 726e336a..cc16bd6c 100644
--- a/tests/integration/voicemessages/VoiceMessagesTest.php
+++ b/tests/integration/voicemessages/VoiceMessagesTest.php
@@ -12,7 +12,7 @@ public function testVoiceMessageCreate()
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
         $Message             = new \MessageBird\Objects\VoiceMessage();
         $Message->originator = 'MessageBird';
-        $Message->recipients = array(31612345678);
+        $Message->recipients = [31612345678];
         $Message->body       = 'This is a test message.';
         $Message->language   = "nl";
         $Message->voice      = "male";
@@ -23,8 +23,8 @@ public function testVoiceMessageCreate()
     public function testListMessage()
     {
         $this->expectException(\MessageBird\Exceptions\ServerException::class);
-        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'voicemessages', array ('offset' => 100, 'limit' => 30), null);
-        $this->client->voicemessages->getList(array ('offset' => 100, 'limit' => 30));
+        $this->mockClient->expects($this->once())->method('performHttpRequest')->with("GET", 'voicemessages',  ['offset' => 100, 'limit' => 30], null);
+        $this->client->voicemessages->getList( ['offset' => 100, 'limit' => 30]);
     }
 
     public function testReadMessage()
diff --git a/tests/unit/RequestValidatorTest.php b/tests/unit/RequestValidatorTest.php
index f01addd8..2b6341bd 100644
--- a/tests/unit/RequestValidatorTest.php
+++ b/tests/unit/RequestValidatorTest.php
@@ -8,7 +8,7 @@ class RequestValidatorTest extends TestCase
 {
     public function testVerify()
     {
-        $query = array(
+        $query = [
             'recipient' => '31612345678',
             'reference' => 'FOO',
             'statusDatetime' => '2019-01-11T09:17:11+00:00',
@@ -16,7 +16,7 @@ public function testVerify()
             'status' => 'delivered',
             'mccmnc' => '20408',
             'ported' => '1',
-        );
+        ];
         $signature = 'KVBdcVdz2lYMwcBLZCRITgxUfA/WkwSi+T3Wxl2HL6w=';
         $requestTimestamp = 1547198231;
         $body = '';
@@ -29,7 +29,7 @@ public function testVerify()
 
     public function testVerifyWithBody()
     {
-        $query = array(
+        $query = [
             'recipient' => '31612345678',
             'reference' => 'FOO',
             'statusDatetime' => '2019-01-11T09:17:11+00:00',
@@ -37,7 +37,7 @@ public function testVerifyWithBody()
             'status' => 'delivered',
             'mccmnc' => '20408',
             'ported' => '1',
-        );
+        ];
         $signature = '2bl+38H4oHVg03pC3bk2LvCB0IHFgfC4cL5HPQ0LdmI=';
         $requestTimestamp = 1547198231;
         $body = '{"foo":"bar"}';
@@ -50,7 +50,7 @@ public function testVerifyWithBody()
 
     public function testVerificationFails()
     {
-        $query = array(
+        $query = [
             'recipient' => '31612345678',
             'reference' => 'BAR',
             'statusDatetime' => '2019-01-11T09:17:11+00:00',
@@ -58,7 +58,7 @@ public function testVerificationFails()
             'status' => 'delivered',
             'mccmnc' => '20408',
             'ported' => '1',
-        );
+        ];
         $signature = 'KVBdcVdz2lYMwcBLZCRITgxUfA/WkwSi+T3Wxl2HL6w=';
         $requestTimestamp = 1547198231;
         $body = '';
@@ -71,7 +71,7 @@ public function testVerificationFails()
 
     public function testRecentRequest()
     {
-        $query = array();
+        $query = [];
         $signature = 'KVBdcVdz2lYMwcBLZCRITgxUfA/WkwSi+T3Wxl2HL6w=';
         $requestTimestamp = time() - 1;
         $body = '';
@@ -84,7 +84,7 @@ public function testRecentRequest()
 
     public function testExpiredRequest()
     {
-        $query = array();
+        $query = [];
         $signature = 'KVBdcVdz2lYMwcBLZCRITgxUfA/WkwSi+T3Wxl2HL6w=';
         $requestTimestamp = time() - 100;
         $body = '';
diff --git a/tests/unit/SignedRequestTest.php b/tests/unit/SignedRequestTest.php
index 56f25de8..ef21fd4d 100644
--- a/tests/unit/SignedRequestTest.php
+++ b/tests/unit/SignedRequestTest.php
@@ -7,7 +7,7 @@ class SignedRequestTest extends TestCase
 {
     public function testCreate()
     {
-        $query = array(
+        $query = [
             'recipient'      => '31612345678',
             'reference'      => 'FOO',
             'statusDatetime' => '2019-01-11T09:17:11+00:00',
@@ -15,7 +15,7 @@ public function testCreate()
             'status'         => 'delivered',
             'mccmnc'         => '20408',
             'ported'         => '1',
-        );
+        ];
         $signature = '2bl+38H4oHVg03pC3bk2LvCB0IHFgfC4cL5HPQ0LdmI=';
         $requestTimestamp = 1547198231;
         $body = '{"foo":"bar"}';
@@ -30,7 +30,7 @@ public function testCreate()
 
     public function testLoadFromArray()
     {
-        $query = array(
+        $query = [
             'recipient' => '31612345678',
             'reference' => 'FOO',
             'statusDatetime' => '2019-01-11T09:17:11+00:00',
@@ -38,18 +38,18 @@ public function testLoadFromArray()
             'status' => 'delivered',
             'mccmnc' => '20408',
             'ported' => '1',
-        );
+        ];
         $signature = '2bl+38H4oHVg03pC3bk2LvCB0IHFgfC4cL5HPQ0LdmI=';
         $requestTimestamp = 1547198231;
         $body = '{"foo":"bar"}';
 
         $request = new SignedRequest();
-        $request->loadFromArray(array(
+        $request->loadFromArray([
             'queryParameters' => $query,
             'signature' => $signature,
             'requestTimestamp' => $requestTimestamp,
             'body' => $body
-        ));
+        ]);
 
         self::assertEquals($requestTimestamp, $request->requestTimestamp);
         self::assertEquals($body, $request->body);
@@ -67,19 +67,19 @@ public function testLoadInvalidQuery()
         $body = '{"foo":"bar"}';
 
         $request = new SignedRequest();
-        $request->loadFromArray(array(
+        $request->loadFromArray([
             'queryParameters' => $query,
             'signature' => $signature,
             'requestTimestamp' => $requestTimestamp,
             'body' => $body
-        ));
+        ]);
     }
 
     public function testLoadInvalidSignature()
     {
         $this->expectException(\MessageBird\Exceptions\ValidationException::class);
         $this->expectExceptionMessage('signature');
-        $query = array(
+        $query = [
             'recipient'      => '31612345678',
             'reference'      => 'FOO',
             'statusDatetime' => '2019-01-11T09:17:11+00:00',
@@ -87,25 +87,25 @@ public function testLoadInvalidSignature()
             'status'         => 'delivered',
             'mccmnc'         => '20408',
             'ported'         => '1',
-        );
+        ];
         $signature = null;
         $requestTimestamp = 1547198231;
         $body = '{"foo":"bar"}';
 
         $request = new SignedRequest();
-        $request->loadFromArray(array(
+        $request->loadFromArray([
             'queryParameters' => $query,
             'signature' => $signature,
             'requestTimestamp' => $requestTimestamp,
             'body' => $body
-        ));
+        ]);
     }
 
     public function testLoadInvalidTimestamp()
     {
         $this->expectException(\MessageBird\Exceptions\ValidationException::class);
         $this->expectExceptionMessage('requestTimestamp');
-        $query = array(
+        $query = [
             'recipient'      => '31612345678',
             'reference'      => 'FOO',
             'statusDatetime' => '2019-01-11T09:17:11+00:00',
@@ -113,25 +113,25 @@ public function testLoadInvalidTimestamp()
             'status'         => 'delivered',
             'mccmnc'         => '20408',
             'ported'         => '1',
-        );
+        ];
         $signature = '2bl+38H4oHVg03pC3bk2LvCB0IHFgfC4cL5HPQ0LdmI=';
         $requestTimestamp = null;
         $body = '{"foo":"bar"}';
 
         $request = new SignedRequest();
-        $request->loadFromArray(array(
+        $request->loadFromArray([
             'queryParameters' => $query,
             'signature' => $signature,
             'requestTimestamp' => $requestTimestamp,
             'body' => $body
-        ));
+        ]);
     }
 
     public function testLoadInvalidBody()
     {
         $this->expectException(\MessageBird\Exceptions\ValidationException::class);
         $this->expectExceptionMessage('body');
-        $query = array(
+        $query = [
             'recipient'      => '31612345678',
             'reference'      => 'FOO',
             'statusDatetime' => '2019-01-11T09:17:11+00:00',
@@ -139,17 +139,17 @@ public function testLoadInvalidBody()
             'status'         => 'delivered',
             'mccmnc'         => '20408',
             'ported'         => '1',
-        );
+        ];
         $signature = '2bl+38H4oHVg03pC3bk2LvCB0IHFgfC4cL5HPQ0LdmI=';
         $requestTimestamp = 1547198231;
         $body = null;
 
         $request = new SignedRequest();
-        $request->loadFromArray(array(
+        $request->loadFromArray([
             'queryParameters' => $query,
             'signature' => $signature,
             'requestTimestamp' => $requestTimestamp,
             'body' => $body
-        ));
+        ]);
     }
 }