diff --git a/src/Pools/EcsPool.cs b/src/Pools/EcsPool.cs
index f7e5502..fc18147 100644
--- a/src/Pools/EcsPool.cs
+++ b/src/Pools/EcsPool.cs
@@ -44,7 +44,7 @@ namespace DCFApixels.DragonECS
         private bool _isHasComponentCopyHandler = EcsComponentCopyHandler<T>.isHasHandler;
 
 #if !DISABLE_POOLS_EVENTS
-        private List<IEcsPoolEventListener> _listeners = new List<IEcsPoolEventListener>();
+        private readonly List<IEcsPoolEventListener> _listeners = new List<IEcsPoolEventListener>();
         private int _listenersCachedCount = 0;
 #endif