diff --git a/src/EcsWorld.cs b/src/EcsWorld.cs
index c01d4cd..0a41088 100644
--- a/src/EcsWorld.cs
+++ b/src/EcsWorld.cs
@@ -356,6 +356,17 @@ namespace DCFApixels.DragonECS
         }
         #endregion
 
+        #region Listeners
+        public void AddListener(IEcsWorldEventListener listener)
+        {
+            _listeners.Add(listener);
+        }
+        public void RemoveListener(IEcsWorldEventListener listener)
+        {
+            _listeners.Remove(listener);
+        }
+        #endregion
+
         #region Debug
         public void GetComponents(int entityID, List<object> list)
         {
diff --git a/src/Executors/EcsQueryExecutor.cs b/src/Executors/EcsQueryExecutor.cs
index ad6db0b..c33cb3f 100644
--- a/src/Executors/EcsQueryExecutor.cs
+++ b/src/Executors/EcsQueryExecutor.cs
@@ -9,8 +9,8 @@
             _world = world;
             OnInitialize();
         }
-        protected abstract void OnInitialize();
         internal void Destroy() => OnDestroy();
+        protected abstract void OnInitialize();
         protected abstract void OnDestroy();
     }
 }