diff --git a/system/src/RocketTheme/Toolbox/Event/Event.php b/system/src/RocketTheme/Toolbox/Event/Event.php
index 412790c7a..20699f74a 100644
--- a/system/src/RocketTheme/Toolbox/Event/Event.php
+++ b/system/src/RocketTheme/Toolbox/Event/Event.php
@@ -6,6 +6,42 @@ use RocketTheme\Toolbox\ArrayTraits\ArrayAccess;
 use RocketTheme\Toolbox\ArrayTraits\Constructor;
 use RocketTheme\Toolbox\ArrayTraits\Export;
 
+if (!class_exists(__NAMESPACE__ . '\\BaseEvent', false)) {
+    if (class_exists(\Symfony\Contracts\EventDispatcher\Event::class)) {
+        /**
+         * @internal Maps to the Symfony Contracts event when available.
+         */
+        abstract class BaseEvent extends \Symfony\Contracts\EventDispatcher\Event
+        {
+        }
+    } elseif (class_exists(\Symfony\Component\EventDispatcher\Event::class)) {
+        /**
+         * @internal Fallback for legacy Symfony Event dispatcher during upgrades.
+         */
+        abstract class BaseEvent extends \Symfony\Component\EventDispatcher\Event
+        {
+        }
+    } else {
+        /**
+         * @internal Minimal stop-propagation implementation used as a last resort.
+         */
+        abstract class BaseEvent
+        {
+            private bool $propagationStopped = false;
+
+            public function isPropagationStopped(): bool
+            {
+                return $this->propagationStopped;
+            }
+
+            public function stopPropagation(): void
+            {
+                $this->propagationStopped = true;
+            }
+        }
+    }
+}
+
 /**
  * Implements Symfony Event interface.
  *
@@ -14,7 +50,7 @@ use RocketTheme\Toolbox\ArrayTraits\Export;
  * @license MIT
  * @deprecated Event classes will be removed in the future. Use PSR-14 implementation instead.
  */
-class Event extends \Symfony\Contracts\EventDispatcher\Event implements \ArrayAccess
+class Event extends BaseEvent implements \ArrayAccess
 {
     use ArrayAccess, Constructor, Export;