diff --git a/src/Symfony/Component/EventDispatcher/ContainerAwareEventDispatcher.php b/src/Symfony/Component/EventDispatcher/ContainerAwareEventDispatcher.php
index 36dafcff39..53a0f6784c 100644
--- a/src/Symfony/Component/EventDispatcher/ContainerAwareEventDispatcher.php
+++ b/src/Symfony/Component/EventDispatcher/ContainerAwareEventDispatcher.php
@@ -141,7 +141,7 @@ class ContainerAwareEventDispatcher extends EventDispatcher
             if (is_string($params)) {
                 $this->listenerIds[$eventName][] = array($serviceId, $params, 0);
             } elseif (is_string($params[0])) {
-                $this->listenerIds[$eventName][] = array($serviceId, $params[0], $params[1]);
+                $this->listenerIds[$eventName][] = array($serviceId, $params[0], isset($params[1]) ? $params[1] : 0);
             } else {
                 foreach ($params as $listener) {
                     $this->listenerIds[$eventName][] = array($serviceId, $listener[0], isset($listener[1]) ? $listener[1] : 0);
diff --git a/src/Symfony/Component/EventDispatcher/Tests/ContainerAwareEventDispatcherTest.php b/src/Symfony/Component/EventDispatcher/Tests/ContainerAwareEventDispatcherTest.php
index 1ce79c33e0..10f5e17d99 100644
--- a/src/Symfony/Component/EventDispatcher/Tests/ContainerAwareEventDispatcherTest.php
+++ b/src/Symfony/Component/EventDispatcher/Tests/ContainerAwareEventDispatcherTest.php
@@ -245,6 +245,8 @@ class SubscriberService implements EventSubscriberInterface
     static function getSubscribedEvents() {
         return array(
             'onEvent' => 'onEvent',
+            'onEvent' => array('onEvent', 10),
+            'onEvent' => array('onEvent'),
         );
     }