diff --git a/README.md b/README.md
index fbd48050..15b90232 100644
--- a/README.md
+++ b/README.md
@@ -83,6 +83,7 @@ $matcher->getError(); // returns null or error message
 * ``inArray($value)``
 * ``oneOf(...$expanders)`` - example usage ``"@string@.oneOf(contains('foo'), contains('bar'), contains('baz'))"``
 * ``matchRegex($regex)`` - example usage ``"@string@.matchRegex('/^lorem.+/')"``
+* ``optional()`` - work's only with ``ArrayMatcher``, ``JsonMatcher`` and ``XmlMatcher``
 
 ##Example usage
 
@@ -237,7 +238,8 @@ $matcher->match(
               'id' => 1,
               'firstName' => 'Norbert',
               'lastName' => 'Orzechowicz',
-              'roles' => array('ROLE_USER')
+              'roles' => array('ROLE_USER'),
+              'position' => 'Developer',
           ),
           array(
               'id' => 2,
@@ -261,7 +263,8 @@ $matcher->match(
               'id' => '@integer@.greaterThan(0)',
               'firstName' => '@string@',
               'lastName' => 'Orzechowicz',
-              'roles' => '@array@'
+              'roles' => '@array@',
+              'position' => '@string@.optional()'
           ),
           array(
               'id' => '@integer@',
@@ -303,7 +306,8 @@ $matcher->match(
         "firstName": @string@,
         "lastName": @string@,
         "created": "@string@.isDateTime()",
-        "roles": @array@
+        "roles": @array@,
+        "posiiton": "@string@.optional()"
       }
     ]
   }'
@@ -347,6 +351,7 @@ XML
   <m:GetStockPrice>
     <m:StockName>@string@</m:StockName>
     <m:StockValue>@string@</m:StockValue>
+    <m:StockQty>@integer@.optional()</m:StockQty>
   </m:GetStockPrice>
 </soap:Body>
 
diff --git a/src/Matcher/ArrayMatcher.php b/src/Matcher/ArrayMatcher.php
index f1de7f1d..bd86f1a8 100644
--- a/src/Matcher/ArrayMatcher.php
+++ b/src/Matcher/ArrayMatcher.php
@@ -2,6 +2,7 @@
 
 namespace Coduo\PHPMatcher\Matcher;
 
+use Coduo\PHPMatcher\Exception\Exception;
 use Coduo\PHPMatcher\Parser;
 use Coduo\ToString\StringConverter;
 use Symfony\Component\PropertyAccess\PropertyAccess;
@@ -153,12 +154,12 @@ function ($item) use ($skipPattern) {
                 }
             );
 
-            $notExistingKeys = array_diff_key($pattern, $values);
-
+            $notExistingKeys = $this->findNotExistingKeys($pattern, $values);
             if (count($notExistingKeys) > 0) {
                 $keyNames = array_keys($notExistingKeys);
                 $path = $this->formatFullPath($parentPath, $this->formatAccessPath($keyNames[0]));
                 $this->setMissingElementInError('value', $path);
+
                 return false;
             }
         }
@@ -166,6 +167,33 @@ function ($item) use ($skipPattern) {
         return true;
     }
 
+    /**
+     * Finds not existing keys
+     * Excludes keys with pattern which includes Optional Expander
+     *
+     * @param $pattern
+     * @param $values
+     * @return array
+     */
+    private function findNotExistingKeys($pattern, $values)
+    {
+        $notExistingKeys = array_diff_key($pattern, $values);
+
+        return array_filter($notExistingKeys, function ($pattern) use ($values) {
+            if (is_array($pattern)) {
+                return !$this->match($values, $pattern);
+            }
+
+            try {
+                $typePattern = $this->parser->parse($pattern);
+            } catch (Exception $e) {
+                return true;
+            }
+
+            return !$typePattern->hasExpander('optional');
+        });
+    }
+
     /**
      * @param $value
      * @param $pattern
diff --git a/src/Matcher/Pattern/Expander/Contains.php b/src/Matcher/Pattern/Expander/Contains.php
index 2fb61173..ebc5927b 100644
--- a/src/Matcher/Pattern/Expander/Contains.php
+++ b/src/Matcher/Pattern/Expander/Contains.php
@@ -7,6 +7,8 @@
 
 final class Contains implements PatternExpander
 {
+    const NAME = 'contains';
+
     /**
      * @var null|string
      */
@@ -22,6 +24,14 @@ final class Contains implements PatternExpander
      */
     private $ignoreCase;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     /**
      * @param $string
      * @param bool $ignoreCase
diff --git a/src/Matcher/Pattern/Expander/Count.php b/src/Matcher/Pattern/Expander/Count.php
index 1698a417..6f14da2f 100644
--- a/src/Matcher/Pattern/Expander/Count.php
+++ b/src/Matcher/Pattern/Expander/Count.php
@@ -7,6 +7,8 @@
 
 final class Count implements PatternExpander
 {
+    const NAME = 'count';
+
     /**
      * @var null|string
      */
@@ -17,6 +19,14 @@ final class Count implements PatternExpander
      */
     private $value;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     /**
      * @param $value
      */
diff --git a/src/Matcher/Pattern/Expander/EndsWith.php b/src/Matcher/Pattern/Expander/EndsWith.php
index 36a8682a..7510a1e3 100644
--- a/src/Matcher/Pattern/Expander/EndsWith.php
+++ b/src/Matcher/Pattern/Expander/EndsWith.php
@@ -7,6 +7,8 @@
 
 final class EndsWith implements PatternExpander
 {
+    const NAME = 'endsWith';
+
     /**
      * @var
      */
@@ -22,6 +24,14 @@ final class EndsWith implements PatternExpander
      */
     private $ignoreCase;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     /**
      * @param string $stringEnding
      * @param bool $ignoreCase
diff --git a/src/Matcher/Pattern/Expander/GreaterThan.php b/src/Matcher/Pattern/Expander/GreaterThan.php
index 8acc4248..a4b1c15b 100644
--- a/src/Matcher/Pattern/Expander/GreaterThan.php
+++ b/src/Matcher/Pattern/Expander/GreaterThan.php
@@ -7,6 +7,8 @@
 
 final class GreaterThan implements PatternExpander
 {
+    const NAME = 'greaterThan';
+
     /**
      * @var
      */
@@ -17,6 +19,14 @@ final class GreaterThan implements PatternExpander
      */
     private $error;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     /**
      * @param $boundary
      */
diff --git a/src/Matcher/Pattern/Expander/InArray.php b/src/Matcher/Pattern/Expander/InArray.php
index c7c10e61..ae8e468a 100644
--- a/src/Matcher/Pattern/Expander/InArray.php
+++ b/src/Matcher/Pattern/Expander/InArray.php
@@ -7,6 +7,8 @@
 
 final class InArray implements PatternExpander
 {
+    const NAME = 'inArray';
+
     /**
      * @var null|string
      */
@@ -17,6 +19,14 @@ final class InArray implements PatternExpander
      */
     private $value;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     /**
      * @param $value
      */
diff --git a/src/Matcher/Pattern/Expander/IsDateTime.php b/src/Matcher/Pattern/Expander/IsDateTime.php
index 1612459f..73c6d651 100644
--- a/src/Matcher/Pattern/Expander/IsDateTime.php
+++ b/src/Matcher/Pattern/Expander/IsDateTime.php
@@ -7,11 +7,21 @@
 
 final class IsDateTime implements PatternExpander
 {
+    const NAME = 'isDateTime';
+
     /**
      * @var null|string
      */
     private $error;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     /**
      * @param string $value
      * @return boolean
diff --git a/src/Matcher/Pattern/Expander/IsEmail.php b/src/Matcher/Pattern/Expander/IsEmail.php
index 337dcc0c..32ccad56 100644
--- a/src/Matcher/Pattern/Expander/IsEmail.php
+++ b/src/Matcher/Pattern/Expander/IsEmail.php
@@ -7,11 +7,21 @@
 
 final class IsEmail implements PatternExpander
 {
+    const NAME = 'isEmail';
+
     /**
      * @var null|string
      */
     private $error;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     /**
      * @param string $value
      * @return boolean
diff --git a/src/Matcher/Pattern/Expander/IsEmpty.php b/src/Matcher/Pattern/Expander/IsEmpty.php
index 673a53e8..dacc6e55 100644
--- a/src/Matcher/Pattern/Expander/IsEmpty.php
+++ b/src/Matcher/Pattern/Expander/IsEmpty.php
@@ -7,8 +7,18 @@
 
 final class IsEmpty implements PatternExpander
 {
+    const NAME = 'isEmpty';
+
     private $error;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     /**
      * @param mixed $value
      *
diff --git a/src/Matcher/Pattern/Expander/IsNotEmpty.php b/src/Matcher/Pattern/Expander/IsNotEmpty.php
index 65b7754c..b5fdfbac 100644
--- a/src/Matcher/Pattern/Expander/IsNotEmpty.php
+++ b/src/Matcher/Pattern/Expander/IsNotEmpty.php
@@ -7,8 +7,18 @@
 
 final class IsNotEmpty implements PatternExpander
 {
+    const NAME = 'isNotEmpty';
+
     private $error;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     /**
      * @param $value
      * @return boolean
diff --git a/src/Matcher/Pattern/Expander/IsUrl.php b/src/Matcher/Pattern/Expander/IsUrl.php
index ca4ad5cf..de45bb78 100644
--- a/src/Matcher/Pattern/Expander/IsUrl.php
+++ b/src/Matcher/Pattern/Expander/IsUrl.php
@@ -7,11 +7,21 @@
 
 final class IsUrl implements PatternExpander
 {
+    const NAME = 'isUrl';
+
     /**
      * @var null|string
      */
     private $error;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     /**
      * @param string $value
      * @return boolean
diff --git a/src/Matcher/Pattern/Expander/LowerThan.php b/src/Matcher/Pattern/Expander/LowerThan.php
index e17a74f7..48df2b8f 100644
--- a/src/Matcher/Pattern/Expander/LowerThan.php
+++ b/src/Matcher/Pattern/Expander/LowerThan.php
@@ -7,6 +7,8 @@
 
 final class LowerThan implements PatternExpander
 {
+    const NAME = 'lowerThan';
+
     /**
      * @var
      */
@@ -17,6 +19,14 @@ final class LowerThan implements PatternExpander
      */
     private $error;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     /**
      * @param $boundary
      */
diff --git a/src/Matcher/Pattern/Expander/MatchRegex.php b/src/Matcher/Pattern/Expander/MatchRegex.php
index 73a83e89..4c5f1ddc 100644
--- a/src/Matcher/Pattern/Expander/MatchRegex.php
+++ b/src/Matcher/Pattern/Expander/MatchRegex.php
@@ -7,6 +7,8 @@
 
 final class MatchRegex implements PatternExpander
 {
+    const NAME = 'matchRegex';
+
     /**
      * @var null|string
      */
@@ -17,6 +19,14 @@ final class MatchRegex implements PatternExpander
      */
     private $pattern;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     /**
      * @param string $pattern
      */
diff --git a/src/Matcher/Pattern/Expander/OneOf.php b/src/Matcher/Pattern/Expander/OneOf.php
index 7407e62e..b8bcb896 100644
--- a/src/Matcher/Pattern/Expander/OneOf.php
+++ b/src/Matcher/Pattern/Expander/OneOf.php
@@ -7,6 +7,8 @@
 
 final class OneOf implements PatternExpander
 {
+    const NAME = 'oneOf';
+
     /**
      * @var PatternExpander[]
      */
@@ -14,6 +16,14 @@ final class OneOf implements PatternExpander
 
     protected $error;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     public function __construct()
     {
         if (func_num_args() < 2) {
diff --git a/src/Matcher/Pattern/Expander/Optional.php b/src/Matcher/Pattern/Expander/Optional.php
new file mode 100644
index 00000000..dbc6a391
--- /dev/null
+++ b/src/Matcher/Pattern/Expander/Optional.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace Coduo\PHPMatcher\Matcher\Pattern\Expander;
+
+use Coduo\PHPMatcher\Matcher\Pattern\PatternExpander;
+
+final class Optional implements PatternExpander
+{
+    const NAME = 'optional';
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function match($value)
+    {
+        return true;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getError()
+    {
+        return null;
+    }
+}
diff --git a/src/Matcher/Pattern/Expander/StartsWith.php b/src/Matcher/Pattern/Expander/StartsWith.php
index e140bb7a..3b5a5b3d 100644
--- a/src/Matcher/Pattern/Expander/StartsWith.php
+++ b/src/Matcher/Pattern/Expander/StartsWith.php
@@ -7,6 +7,8 @@
 
 final class StartsWith implements PatternExpander
 {
+    const NAME = 'startsWith';
+
     /**
      * @var
      */
@@ -22,6 +24,14 @@ final class StartsWith implements PatternExpander
      */
     private $ignoreCase;
 
+    /**
+     * {@inheritdoc}
+     */
+    public static function is(string $name)
+    {
+        return self::NAME === $name;
+    }
+
     /**
      * @param string $stringBeginning
      * @param bool $ignoreCase
diff --git a/src/Matcher/Pattern/Pattern.php b/src/Matcher/Pattern/Pattern.php
index 6f29103d..35d7792d 100644
--- a/src/Matcher/Pattern/Pattern.php
+++ b/src/Matcher/Pattern/Pattern.php
@@ -21,4 +21,13 @@ public function matchExpanders($value);
      * @return null|string
      */
     public function getError();
+
+    /**
+     * Checks whether a Pattern has added Expander.
+     *
+     * @param string $expanderName The name of the expander
+     *
+     * @return bool true if the specified pattern has expander, false otherwise
+     */
+    public function hasExpander(string $expanderName);
 }
diff --git a/src/Matcher/Pattern/PatternExpander.php b/src/Matcher/Pattern/PatternExpander.php
index 30178b3a..5e31d733 100644
--- a/src/Matcher/Pattern/PatternExpander.php
+++ b/src/Matcher/Pattern/PatternExpander.php
@@ -4,6 +4,12 @@
 
 interface PatternExpander
 {
+    /**
+     * @param string $name
+     * @return bool
+     */
+    public static function is(string $name);
+
     /**
      * @param $value
      * @return boolean
diff --git a/src/Matcher/Pattern/TypePattern.php b/src/Matcher/Pattern/TypePattern.php
index fcbc17ae..ae36f395 100644
--- a/src/Matcher/Pattern/TypePattern.php
+++ b/src/Matcher/Pattern/TypePattern.php
@@ -69,10 +69,24 @@ public function matchExpanders($value)
     }
 
     /**
-     * @return null|string
+     * {@inheritdoc}
      */
     public function getError()
     {
         return $this->error;
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function hasExpander(string $expanderName)
+    {
+        foreach ($this->expanders as $expander) {
+            if ($expander::is($expanderName)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
 }
diff --git a/src/Parser/ExpanderInitializer.php b/src/Parser/ExpanderInitializer.php
index 9f21bcd7..cc9b3dcb 100644
--- a/src/Parser/ExpanderInitializer.php
+++ b/src/Parser/ExpanderInitializer.php
@@ -2,35 +2,36 @@
 
 namespace Coduo\PHPMatcher\Parser;
 
-use Coduo\PHPMatcher\AST\Expander;
+use Coduo\PHPMatcher\AST\Expander as ExpanderNode;
 use Coduo\PHPMatcher\Exception\InvalidArgumentException;
 use Coduo\PHPMatcher\Exception\InvalidExpanderTypeException;
 use Coduo\PHPMatcher\Exception\UnknownExpanderClassException;
 use Coduo\PHPMatcher\Exception\UnknownExpanderException;
 use Coduo\PHPMatcher\Matcher\Pattern\PatternExpander;
+use Coduo\PHPMatcher\Matcher\Pattern\Expander;
 
 final class ExpanderInitializer
 {
     /**
      * @var array
      */
-    private $expanderDefinitions = array(
-        "startsWith" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\StartsWith",
-        "endsWith" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\EndsWith",
-        "isNotEmpty" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\IsNotEmpty",
-        "isEmpty" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\IsEmpty",
-        "isDateTime" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\IsDateTime",
-        "isEmail" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\IsEmail",
-        "isUrl" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\IsUrl",
-        "lowerThan" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\LowerThan",
-        "greaterThan" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\GreaterThan",
-        "inArray" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\InArray",
-        "count" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\Count",
-        "contains" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\Contains",
-        "matchRegex" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\MatchRegex",
-
-        "oneOf" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\OneOf"
-    );
+    private $expanderDefinitions = [
+        Expander\Contains::NAME => Expander\Contains::class,
+        Expander\Count::NAME => Expander\Count::class,
+        Expander\EndsWith::NAME => Expander\EndsWith::class,
+        Expander\GreaterThan::NAME => Expander\GreaterThan::class,
+        Expander\InArray::NAME => Expander\InArray::class,
+        Expander\IsDateTime::NAME => Expander\IsDateTime::class,
+        Expander\IsEmail::NAME => Expander\IsEmail::class,
+        Expander\IsEmpty::NAME => Expander\IsEmpty::class,
+        Expander\IsNotEmpty::NAME => Expander\IsNotEmpty::class,
+        Expander\IsUrl::NAME => Expander\IsUrl::class,
+        Expander\LowerThan::NAME => Expander\LowerThan::class,
+        Expander\MatchRegex::NAME => Expander\MatchRegex::class,
+        Expander\OneOf::NAME => Expander\OneOf::class,
+        Expander\Optional::NAME => Expander\Optional::class,
+        Expander\StartsWith::NAME => Expander\StartsWith::class,
+    ];
 
     /**
      * @param string $expanderName
@@ -70,12 +71,12 @@ public function getExpanderDefinition($expanderName)
     }
 
     /**
-     * @param Expander $expanderNode
+     * @param ExpanderNode $expanderNode
      * @throws InvalidExpanderTypeException
      * @throws UnknownExpanderException
      * @return PatternExpander
      */
-    public function initialize(Expander $expanderNode)
+    public function initialize(ExpanderNode $expanderNode)
     {
         if (!array_key_exists($expanderNode->getName(), $this->expanderDefinitions)) {
             throw new UnknownExpanderException(sprintf("Unknown expander \"%s\"", $expanderNode->getName()));
@@ -86,7 +87,7 @@ public function initialize(Expander $expanderNode)
         if ($expanderNode->hasArguments()) {
             $arguments = array();
             foreach ($expanderNode->getArguments() as $argument) {
-                $arguments[] = ($argument instanceof Expander)
+                $arguments[] = ($argument instanceof ExpanderNode)
                     ? $this->initialize($argument)
                     : $argument;
             }
diff --git a/tests/Matcher/Pattern/Expander/OptionalTest.php b/tests/Matcher/Pattern/Expander/OptionalTest.php
new file mode 100644
index 00000000..ef8b0a87
--- /dev/null
+++ b/tests/Matcher/Pattern/Expander/OptionalTest.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace Coduo\PHPMatcher\Tests\Matcher\Pattern\Expander;
+
+use Coduo\PHPMatcher\Matcher\Pattern\Expander\Optional;
+
+class OptionalTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @dataProvider examplesProvider
+     */
+    public function test_optional_expander_match($value, $expectedResult)
+    {
+        $expander = new Optional();
+        $this->assertEquals($expectedResult, $expander->match($value));
+    }
+
+    public static function examplesProvider()
+    {
+        return array(
+            array(array(), true),
+            array(array('data'), true),
+            array('', true),
+            array(0, true),
+            array(10.1, true),
+            array(null, true),
+            array('Lorem ipsum', true),
+        );
+    }
+}
diff --git a/tests/Matcher/Pattern/PatternTest.php b/tests/Matcher/Pattern/PatternTest.php
new file mode 100644
index 00000000..185af9c0
--- /dev/null
+++ b/tests/Matcher/Pattern/PatternTest.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace Coduo\PHPMatcher\Tests\Matcher\Pattern;
+
+use Coduo\PHPMatcher\Matcher\Pattern\Expander\IsEmail;
+use Coduo\PHPMatcher\Matcher\Pattern\Expander\IsEmpty;
+use Coduo\PHPMatcher\Matcher\Pattern\Expander\Optional;
+use Coduo\PHPMatcher\Matcher\Pattern\Pattern;
+use Coduo\PHPMatcher\Matcher\Pattern\TypePattern;
+
+class PatternTest  extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @var Pattern
+     */
+    private $pattern;
+
+    public function setUp()
+    {
+        $this->pattern = new TypePattern('dummy');
+        $this->pattern->addExpander(new isEmail());
+        $this->pattern->addExpander(new isEmpty());
+        $this->pattern->addExpander(new Optional());
+    }
+
+    /**
+     * @dataProvider examplesProvider
+     */
+    public function test_has_expander($expander, $expectedResult)
+    {
+        $this->assertEquals($expectedResult, $this->pattern->hasExpander($expander));
+    }
+
+    public static function examplesProvider()
+    {
+        return array(
+            array("isEmail", true),
+            array("isEmpty", true),
+            array("optional", true),
+            array("isUrl", false),
+            array("non existing expander", false),
+        );
+    }
+}
diff --git a/tests/MatcherTest.php b/tests/MatcherTest.php
index bdeebf27..6d750205 100644
--- a/tests/MatcherTest.php
+++ b/tests/MatcherTest.php
@@ -175,6 +175,23 @@ public function jsonDataProvider()
                     "nextPage": "@string@"
                 }',
             ),
+            'excludes missing property from match for optional property' => array(
+                /** @lang JSON */
+                '{
+                    "users":[],
+                    "prevPage": "http:\/\/example.com\/api\/users\/1?limit=2",
+                    "currPage": 2
+                }',
+                /** @lang JSON */
+                '{
+                    "users":[
+                        "@...@"                        
+                    ],
+                    "prevPage": "@string@.optional()",
+                    "nextPage": "@string@.optional()",
+                    "currPage": "@integer@.optional()"
+                }',
+            ),
         );
     }
 
@@ -208,6 +225,46 @@ public function test_matcher_with_xml()
   </m:GetStockPrice>
 </soap:Body>
 
+</soap:Envelope>
+XML;
+
+        $this->assertTrue($this->matcher->match($xml, $xmlPattern));
+        $this->assertTrue(PHPMatcher::match($xml, $xmlPattern));
+    }
+
+
+
+    public function test_matcher_with_xml_including_optional_node()
+    {
+        $xml = <<<XML
+<?xml version="1.0"?>
+<soap:Envelope
+xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
+soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">
+
+<soap:Body xmlns:m="http://www.example.org/stock">
+  <m:GetStockPrice>
+    <m:StockName>IBM</m:StockName>
+    <m:StockValue>Any Value</m:StockValue>
+  </m:GetStockPrice>
+</soap:Body>
+
+</soap:Envelope>
+XML;
+        $xmlPattern = <<<XML
+<?xml version="1.0"?>
+<soap:Envelope
+    xmlns:soap="@string@"
+            soap:encodingStyle="@string@">
+
+<soap:Body xmlns:m="@string@">
+  <m:GetStockPrice>
+    <m:StockName>@string@.optional()</m:StockName>
+    <m:StockValue>@string@.optional()</m:StockValue>
+    <m:StockQty>@integer@.optional()</m:StockQty>
+  </m:GetStockPrice>
+</soap:Body>
+
 </soap:Envelope>
 XML;