diff --git a/src/EventDispatcher/EventDispatcher.php b/src/EventDispatcher/EventDispatcher.php
index c4865688a..9f1f77c1a 100644
--- a/src/EventDispatcher/EventDispatcher.php
+++ b/src/EventDispatcher/EventDispatcher.php
@@ -51,7 +51,7 @@ public function setListeners(array $listeners)
 
     public function addListener($eventName, $callable, $class = null, $format = null)
     {
-        $this->listeners[$eventName][] = array($callable, null === $class ? null : strtolower($class), $format);
+        $this->listeners[$eventName][] = array($callable, null === $class ? null : $class, $format);
         unset($this->classListeners[$eventName]);
     }
 
@@ -63,7 +63,7 @@ public function addSubscriber(EventSubscriberInterface $subscriber)
             }
 
             $method = isset($eventData['method']) ? $eventData['method'] : self::getDefaultMethodName($eventData['event']);
-            $class = isset($eventData['class']) ? strtolower($eventData['class']) : null;
+            $class = isset($eventData['class']) ? $eventData['class'] : null;
             $format = isset($eventData['format']) ? $eventData['format'] : null;
             $this->listeners[$eventData['event']][] = array(array($subscriber, $method), $class, $format);
             unset($this->classListeners[$eventData['event']]);
@@ -76,12 +76,11 @@ public function hasListeners($eventName, $class, $format)
             return false;
         }
 
-        $loweredClass = strtolower($class);
-        if (!isset($this->classListeners[$eventName][$loweredClass][$format])) {
-            $this->classListeners[$eventName][$loweredClass][$format] = $this->initializeListeners($eventName, $loweredClass, $format);
+        if (!isset($this->classListeners[$eventName][$class][$format])) {
+            $this->classListeners[$eventName][$class][$format] = $this->initializeListeners($eventName, $class, $format);
         }
 
-        return !!$this->classListeners[$eventName][$loweredClass][$format];
+        return !!$this->classListeners[$eventName][$class][$format];
     }
 
     public function dispatch($eventName, $class, $format, Event $event)
@@ -90,18 +89,17 @@ public function dispatch($eventName, $class, $format, Event $event)
             return;
         }
 
-        $loweredClass = strtolower($class);
-        if (!isset($this->classListeners[$eventName][$loweredClass][$format])) {
-            $this->classListeners[$eventName][$loweredClass][$format] = $this->initializeListeners($eventName, $loweredClass, $format);
+        if (!isset($this->classListeners[$eventName][$class][$format])) {
+            $this->classListeners[$eventName][$class][$format] = $this->initializeListeners($eventName, $class, $format);
         }
 
-        foreach ($this->classListeners[$eventName][$loweredClass][$format] as $listener) {
+        foreach ($this->classListeners[$eventName][$class][$format] as $listener) {
 
             if ($event->isPropagationStopped()) {
                 break;
             }
 
-            \call_user_func($listener, $event, $eventName, $loweredClass, $format, $this);
+            \call_user_func($listener, $event, $eventName, $class, $format, $this);
         }
     }
 
diff --git a/tests/Serializer/EventDispatcher/EventDispatcherTest.php b/tests/Serializer/EventDispatcher/EventDispatcherTest.php
index ac8b0866e..b7cff25b6 100644
--- a/tests/Serializer/EventDispatcher/EventDispatcherTest.php
+++ b/tests/Serializer/EventDispatcher/EventDispatcherTest.php
@@ -18,11 +18,13 @@
 
 namespace JMS\Serializer\Tests\Serializer\EventDispatcher;
 
+use JMS\Serializer\Context;
 use JMS\Serializer\EventDispatcher\Event;
 use JMS\Serializer\EventDispatcher\EventDispatcher;
 use JMS\Serializer\EventDispatcher\EventDispatcherInterface;
 use JMS\Serializer\EventDispatcher\EventSubscriberInterface;
 use JMS\Serializer\EventDispatcher\ObjectEvent;
+use PHPUnit\Framework\Assert;
 
 class EventDispatcherTest extends \PHPUnit_Framework_TestCase
 {
@@ -55,13 +57,13 @@ public function testHasListeners()
         $this->dispatcher->addListener('baz', function () {
         }, 'Bar');
         $this->assertTrue($this->dispatcher->hasListeners('baz', 'Bar', 'xml'));
-        $this->assertTrue($this->dispatcher->hasListeners('baz', 'bAr', 'xml'));
+        //$this->assertTrue($this->dispatcher->hasListeners('baz', 'bAr', 'xml'));
     }
 
     public function testDispatch()
     {
         $a = new MockListener();
-        $this->dispatcher->addListener('foo', array($a, 'foo'));
+        $this->dispatcher->addListener('foo', array($a, 'Foo'));
         $this->dispatch('bar');
         $a->_verify('Listener is not called for other event.');
 
@@ -70,10 +72,11 @@ public function testDispatch()
         $this->dispatcher->addListener('pre', array($b, 'foo'), 'Foo');
         $this->dispatcher->addListener('pre', array($b, 'all'));
 
-        $b->bar($this->event, 'pre', 'bar', 'json', $this->dispatcher);
-        $b->all($this->event, 'pre', 'bar', 'json', $this->dispatcher);
-        $b->foo($this->event, 'pre', 'foo', 'json', $this->dispatcher);
-        $b->all($this->event, 'pre', 'foo', 'json', $this->dispatcher);
+        $b->bar($this->event, 'pre', 'Bar', 'json', $this->dispatcher);
+        $b->all($this->event, 'pre', 'Bar', 'json', $this->dispatcher);
+        $b->foo($this->event, 'pre', 'Foo', 'json', $this->dispatcher);
+        $b->all($this->event, 'pre', 'Foo', 'json', $this->dispatcher);
+
         $b->_replay();
         $this->dispatch('pre', 'Bar');
         $this->dispatch('pre', 'Foo');
@@ -113,7 +116,7 @@ public function testListenerCanDispatchEvent()
 
             $this->assertSame('pre', $eventName);
             $this->assertSame('json', $format);
-            $this->assertSame('foo', $loweredClass);
+            $this->assertSame('Foo', $loweredClass);
 
             $dispatcher->dispatch('post', 'Blah', 'xml', $event);
         });
@@ -127,7 +130,7 @@ public function testListenerCanDispatchEvent()
 
             $this->assertSame('post', $eventName);
             $this->assertSame('xml', $format);
-            $this->assertSame('blah', $loweredClass);
+            $this->assertSame('Blah', $loweredClass);
         });
 
         $this->dispatch('pre');
@@ -159,7 +162,7 @@ public function testAddSubscriber()
     protected function setUp()
     {
         $this->dispatcher = $this->createEventDispatcher();
-        $this->event = new ObjectEvent($this->getMockBuilder('JMS\Serializer\Context')->getMock(), new \stdClass(), array('name' => 'foo', 'params' => array()));
+        $this->event = new ObjectEvent($this->getMockBuilder(Context::class)->getMock(), new \stdClass(), array('name' => 'foo', 'params' => array()));
     }
 
     protected function createEventDispatcher()
@@ -207,6 +210,6 @@ public function _replay()
 
     public function _verify($message = null)
     {
-        \PHPUnit_Framework_Assert::assertSame($this->expected, $this->actual, $message);
+        Assert::assertSame($this->expected, $this->actual, $message);
     }
 }
diff --git a/tests/Serializer/EventDispatcher/LazyEventDispatcherTest.php b/tests/Serializer/EventDispatcher/LazyEventDispatcherTest.php
index ca392596a..aeeb620fa 100644
--- a/tests/Serializer/EventDispatcher/LazyEventDispatcherTest.php
+++ b/tests/Serializer/EventDispatcher/LazyEventDispatcherTest.php
@@ -57,10 +57,10 @@ public function testDispatchWithListenerAsService()
         $this->dispatcher->addListener('pre', array('b', 'foo'), 'Foo');
         $this->dispatcher->addListener('pre', array('b', 'all'));
 
-        $b->bar($this->event, 'pre', 'bar', 'json', $this->dispatcher);
-        $b->all($this->event, 'pre', 'bar', 'json', $this->dispatcher);
-        $b->foo($this->event, 'pre', 'foo', 'json', $this->dispatcher);
-        $b->all($this->event, 'pre', 'foo', 'json', $this->dispatcher);
+        $b->bar($this->event, 'pre', 'Bar', 'json', $this->dispatcher);
+        $b->all($this->event, 'pre', 'Bar', 'json', $this->dispatcher);
+        $b->foo($this->event, 'pre', 'Foo', 'json', $this->dispatcher);
+        $b->all($this->event, 'pre', 'Foo', 'json', $this->dispatcher);
         $b->_replay();
         $this->dispatch('pre', 'Bar');
         $this->dispatch('pre', 'Foo');