diff --git a/src/Symfony/Component/Intl/DateFormatter/DateFormat/TimeZoneTransformer.php b/src/Symfony/Component/Intl/DateFormatter/DateFormat/TimeZoneTransformer.php
index adca3eeb7dcea..6f9c0d5a02bb5 100644
--- a/src/Symfony/Component/Intl/DateFormatter/DateFormat/TimeZoneTransformer.php
+++ b/src/Symfony/Component/Intl/DateFormatter/DateFormat/TimeZoneTransformer.php
@@ -29,7 +29,7 @@ public function format(\DateTime $dateTime, $length)
     {
         $timeZone = substr($dateTime->getTimezone()->getName(), 0, 3);
 
-        if (!in_array($timeZone, array('Etc', 'UTC'))) {
+        if (!in_array($timeZone, array('Etc', 'UTC', 'GMT'))) {
             throw new NotImplementedException('Time zone different than GMT or UTC is not supported as a formatting output.');
         }
 
diff --git a/src/Symfony/Component/Intl/NumberFormatter/NumberFormatter.php b/src/Symfony/Component/Intl/NumberFormatter/NumberFormatter.php
index 07c8e84c861bf..0ee222ee50fd6 100644
--- a/src/Symfony/Component/Intl/NumberFormatter/NumberFormatter.php
+++ b/src/Symfony/Component/Intl/NumberFormatter/NumberFormatter.php
@@ -773,7 +773,7 @@ private function isInitializedAttribute($attr)
      * @param mixed $value The value to be converted
      * @param int   $type  The type to convert. Can be TYPE_DOUBLE (float) or TYPE_INT32 (int)
      *
-     * @return int|float The converted value
+     * @return int|float|false The converted value
      */
     private function convertValueDataType($value, $type)
     {
@@ -793,7 +793,7 @@ private function convertValueDataType($value, $type)
      *
      * @param mixed $value The value to be converted
      *
-     * @return int The converted value
+     * @return int|false The converted value
      */
     private function getInt32Value($value)
     {
@@ -809,7 +809,7 @@ private function getInt32Value($value)
      *
      * @param mixed $value The value to be converted
      *
-     * @return int|float The converted value
+     * @return int|float|false The converted value
      *
      * @see https://bugs.php.net/bug.php?id=59597 Bug #59597
      */
diff --git a/src/Symfony/Component/Intl/Tests/DateFormatter/AbstractIntlDateFormatterTest.php b/src/Symfony/Component/Intl/Tests/DateFormatter/AbstractIntlDateFormatterTest.php
index 259f5e5d9d5c4..0603394fe1f6d 100644
--- a/src/Symfony/Component/Intl/Tests/DateFormatter/AbstractIntlDateFormatterTest.php
+++ b/src/Symfony/Component/Intl/Tests/DateFormatter/AbstractIntlDateFormatterTest.php
@@ -392,14 +392,21 @@ public function testFormatWithConstructorTimezone()
         );
     }
 
-    public function testFormatWithDateTimeZone()
+    public function testFormatWithDateTimeZoneGmt()
     {
         if (PHP_VERSION_ID < 50500) {
             $this->markTestSkipped('Only in PHP 5.5+ IntlDateFormatter allows to use DateTimeZone objects.');
         }
 
-        if (defined('HHVM_VERSION_ID')) {
-            $this->markTestSkipped('This test cannot work on HHVM. See https://github.com/facebook/hhvm/issues/5875 for the issue.');
+        $formatter = $this->getDateFormatter('en', IntlDateFormatter::MEDIUM, IntlDateFormatter::SHORT, new \DateTimeZone('GMT'), IntlDateFormatter::GREGORIAN, 'zzzz');
+
+        $this->assertEquals('GMT', $formatter->format(0));
+    }
+
+    public function testFormatWithDateTimeZoneGmtOffset()
+    {
+        if (defined('HHVM_VERSION_ID') || PHP_VERSION_ID <= 50509) {
+            $this->markTestSkipped('DateTimeZone GMT offsets are supported since 5.5.10. See https://github.com/facebook/hhvm/issues/5875 for HHVM.');
         }
 
         $formatter = $this->getDateFormatter('en', IntlDateFormatter::MEDIUM, IntlDateFormatter::SHORT, new \DateTimeZone('GMT+03:00'), IntlDateFormatter::GREGORIAN, 'zzzz');