diff --git a/src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php b/src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php
index 9c88809de059..3ae1136c4c97 100644
--- a/src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php
+++ b/src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php
@@ -56,12 +56,12 @@ public function process(ContainerBuilder $container)
             return;
         }
 
+        $aliases = [];
+
         if ($container->hasParameter($this->eventAliasesParameter)) {
             $aliases = $container->getParameter($this->eventAliasesParameter);
-            $container->getParameterBag()->remove($this->eventAliasesParameter);
-        } else {
-            $aliases = [];
         }
+
         $definition = $container->findDefinition($this->dispatcherService);
 
         foreach ($container->findTaggedServiceIds($this->listenerTag, true) as $id => $events) {
diff --git a/src/Symfony/Component/EventDispatcher/Tests/DependencyInjection/RegisterListenersPassTest.php b/src/Symfony/Component/EventDispatcher/Tests/DependencyInjection/RegisterListenersPassTest.php
index 5252664a9f99..42870b88876e 100644
--- a/src/Symfony/Component/EventDispatcher/Tests/DependencyInjection/RegisterListenersPassTest.php
+++ b/src/Symfony/Component/EventDispatcher/Tests/DependencyInjection/RegisterListenersPassTest.php
@@ -213,17 +213,22 @@ public function testInvokableEventListener()
     public function testAliasedEventListener(): void
     {
         $container = new ContainerBuilder();
-        $container->setParameter('event_dispatcher.event_aliases', [AliasedEvent::class => 'aliased_event']);
+        $eventAliases = [AliasedEvent::class => 'aliased_event'];
+        $container->setParameter('event_dispatcher.event_aliases', $eventAliases);
         $container->register('foo', InvokableListenerService::class)->addTag('kernel.event_listener', ['event' => AliasedEvent::class, 'method' => 'onEvent']);
         $container->register('bar', InvokableListenerService::class)->addTag('kernel.event_listener', ['event' => CustomEvent::class, 'method' => 'onEvent']);
         $container->register('event_dispatcher');
 
-        $eventAliasPass = new AddEventAliasesPass([CustomEvent::class => 'custom_event']);
+        $customEventAlias = [CustomEvent::class => 'custom_event'];
+        $eventAliasPass = new AddEventAliasesPass($customEventAlias);
         $eventAliasPass->process($container);
 
         $registerListenersPass = new RegisterListenersPass();
         $registerListenersPass->process($container);
 
+        $this->assertTrue($container->hasParameter('event_dispatcher.event_aliases'));
+        $this->assertSame(array_merge($eventAliases, $customEventAlias), $container->getParameter('event_dispatcher.event_aliases'));
+
         $definition = $container->getDefinition('event_dispatcher');
         $expectedCalls = [
             [