diff --git a/.travis.yml b/.travis.yml
index 507e536d..87d7ed89 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,7 +6,7 @@ php:
   - '5.6'
   - '7.0'
   - '7.1'
-#  - hhvm # on Trusty only
+  - hhvm # on Trusty only
 #  - nightly
 
 cache:
@@ -18,6 +18,8 @@ matrix:
   include:
     - php: '5.6'
       env: STREAM_CLIENT_ONLY=1
+    - php: hhvm
+      env: STREAM_CLIENT_ONLY=1
 
 before_install:
   - nvm install 6.11
diff --git a/src/Parse/HttpClients/ParseStreamHttpClient.php b/src/Parse/HttpClients/ParseStreamHttpClient.php
index 4c9b29aa..bda4e3e0 100644
--- a/src/Parse/HttpClients/ParseStreamHttpClient.php
+++ b/src/Parse/HttpClients/ParseStreamHttpClient.php
@@ -209,7 +209,15 @@ public function send($url, $method = 'GET', $data = array())
             if ($method == "GET") {
                 // handle GET
                 $query = http_build_query($data, null, '&');
-                $this->options['http']['content'] = $query;
+
+                if (!defined('HHVM_VERSION')) {
+                    $this->options['http']['content'] = $query;
+                } else {
+                    // HHVM doesn't reapply 'content' to the url
+                    // have to do it ourselves
+                    $url.='?'.$query;
+                }
+
                 $this->addRequestHeader('Content-type', 'application/x-www-form-urlencoded');
             } elseif ($method == "POST") {
                 // handle POST
@@ -221,7 +229,21 @@ public function send($url, $method = 'GET', $data = array())
         }
 
         // set headers
-        $this->options['http']['header'] = $this->buildRequestHeaders();
+        if (!defined('HHVM_VERSION')) {
+            // default
+            $this->options['http']['header'] = $this->buildRequestHeaders();
+        } else {
+            /**
+             * HHVM bug bypass
+             * Passing via 'header' ends up duplicating all custom headers submitted due to a bug in HHVM.
+             * We can bypass this through the separate 'user_agent' field, as it is never sanitized,
+             * so we can append our desired headers after the initial user-agent string.
+             * Note that this works in php5 as well (probably 7 and up too),
+             * but for now we use this only where we need it.
+             * Source: https://github.com/facebook/hhvm/blob/master/hphp/runtime/base/http-stream-wrapper.cpp#L92
+             */
+            $this->options['http']['user_agent'] = "parse-php-sdk\r\n".$this->buildRequestHeaders();
+        }
 
         // create a stream context
         $this->parseStream->createContext($this->options);
diff --git a/src/Parse/ParsePolygon.php b/src/Parse/ParsePolygon.php
index f5582748..4eaf64ed 100755
--- a/src/Parse/ParsePolygon.php
+++ b/src/Parse/ParsePolygon.php
@@ -50,7 +50,7 @@ public function setCoordinates($coords)
         }
         $points = [];
         foreach ($coords as $coord) {
-            $geoPoint;
+            $geoPoint = null;
             if ($coord instanceof ParseGeoPoint) {
                 $geoPoint = $coord;
             } elseif (is_array($coord) && count($coord) === 2) {
diff --git a/tests/Parse/ParseStreamHttpClientTest.php b/tests/Parse/ParseStreamHttpClientTest.php
index 9cd8eef5..061bcf70 100644
--- a/tests/Parse/ParseStreamHttpClientTest.php
+++ b/tests/Parse/ParseStreamHttpClientTest.php
@@ -14,6 +14,9 @@
 
 class ParseStreamHttpClientTest extends \PHPUnit_Framework_TestCase
 {
+    /**
+     * @group test-get-response
+     */
     public function testGetResponse()
     {
         $client = new ParseStreamHttpClient();
@@ -25,7 +28,7 @@ public function testGetResponse()
         // get response headers
         $headers = $client->getResponseHeaders();
 
-        $this->assertEquals('HTTP/1.0 200 OK', $headers['http_code']);
+        $this->assertTrue(preg_match('|HTTP/1\.\d\s200\sOK|', $headers['http_code']) === 1);
     }
 
     public function testInvalidUrl()