diff --git a/src/Symfony/Component/EventDispatcher/EventDispatcher.php b/src/Symfony/Component/EventDispatcher/EventDispatcher.php
index f7c6630982..221fdc8f53 100644
--- a/src/Symfony/Component/EventDispatcher/EventDispatcher.php
+++ b/src/Symfony/Component/EventDispatcher/EventDispatcher.php
@@ -270,7 +270,7 @@ class EventDispatcher implements EventDispatcherInterface
         $this->sorted[$eventName] = [];
 
         foreach ($this->listeners[$eventName] as &$listeners) {
-            foreach ($listeners as $k => $listener) {
+            foreach ($listeners as $k => &$listener) {
                 if (\is_array($listener) && isset($listener[0]) && $listener[0] instanceof \Closure) {
                     $listener[0] = $listener[0]();
                 }