diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8f650a41..44878882 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## Unreleased
  - Use `jean85/pretty-package-versions` `^1.5` to leverage the new `getRootPackageVersion` method (c8799ac)
+ - Fix support for PHP preloading (#354, thanks to @annuh)
 
 ## 3.5.1 (2020-05-07)
  - Capture events using the `Hub` in the `MessengerListener` to avoid loosing `Scope` data (#339, thanks to @sh41)
diff --git a/src/EventListener/RequestListener.php b/src/EventListener/RequestListener.php
index b305c7d1..f9bc0c71 100644
--- a/src/EventListener/RequestListener.php
+++ b/src/EventListener/RequestListener.php
@@ -14,11 +14,19 @@
 use Symfony\Component\Security\Core\User\UserInterface;
 
 if (Kernel::MAJOR_VERSION >= 5) {
-    class_alias(RequestEvent::class, RequestListenerRequestEvent::class);
-    class_alias(ControllerEvent::class, RequestListenerControllerEvent::class);
+    if (! class_exists(RequestListenerRequestEvent::class, false)) {
+        class_alias(RequestEvent::class, RequestListenerRequestEvent::class);
+    }
+    if (! class_exists(RequestListenerControllerEvent::class, false)) {
+        class_alias(ControllerEvent::class, RequestListenerControllerEvent::class);
+    }
 } else {
-    class_alias(GetResponseEvent::class, RequestListenerRequestEvent::class);
-    class_alias(FilterControllerEvent::class, RequestListenerControllerEvent::class);
+    if (! class_exists(RequestListenerRequestEvent::class, false)) {
+        class_alias(GetResponseEvent::class, RequestListenerRequestEvent::class);
+    }
+    if (! class_exists(RequestListenerControllerEvent::class, false)) {
+        class_alias(FilterControllerEvent::class, RequestListenerControllerEvent::class);
+    }
 }
 
 /**