diff --git a/event_dispatcher.rst b/event_dispatcher.rst
index b162fe035f1..c7fa7b7d905 100644
--- a/event_dispatcher.rst
+++ b/event_dispatcher.rst
@@ -289,6 +289,8 @@ This alias mapping can be extended for custom events by registering the
 compiler pass ``AddEventAliasesPass``::
 
     // src/Kernel.php
+    namespace App;
+
     use App\Event\MyCustomEvent;
     use Symfony\Component\DependencyInjection\ContainerBuilder;
     use Symfony\Component\EventDispatcher\DependencyInjection\AddEventAliasesPass;