diff --git a/src/Buildin/UnityComponents.cs b/src/Buildin/UnityComponents.cs
index 57f5e73..da22fbd 100644
--- a/src/Buildin/UnityComponents.cs
+++ b/src/Buildin/UnityComponents.cs
@@ -43,7 +43,7 @@ namespace DCFApixels.DragonECS
         {
             get { return UnityComponentConsts.BaseGroup; }
         }
-        public sealed override void Apply(int worldID, int entityID)
+        public sealed override void Apply(short worldID, int entityID)
         {
             EcsWorld.GetPoolInstance<EcsPool<UnityComponent<T>>>(worldID).TryAddOrGet(entityID) = component;
         }
diff --git a/src/EntityTemplate/Templates/ComponentTemplateBase.cs b/src/EntityTemplate/Templates/ComponentTemplateBase.cs
index 288b663..9ed12f5 100644
--- a/src/EntityTemplate/Templates/ComponentTemplateBase.cs
+++ b/src/EntityTemplate/Templates/ComponentTemplateBase.cs
@@ -46,7 +46,7 @@ namespace DCFApixels.DragonECS
         public virtual void OnGizmos(Transform transform, GizmosMode mode) { }
         public virtual void OnValidate(UnityEngine.Object obj) { }
 
-        public abstract void Apply(int worldID, int entityID);
+        public abstract void Apply(short worldID, int entityID);
         #endregion
     }
     [Serializable]
@@ -80,7 +80,7 @@ namespace DCFApixels.DragonECS
     public abstract class ComponentTemplate<T> : ComponentTemplateBase<T>
         where T : struct, IEcsComponent
     {
-        public override void Apply(int worldID, int entityID)
+        public override void Apply(short worldID, int entityID)
         {
             EcsWorld.GetPoolInstance<EcsPool<T>>(worldID).TryAddOrGet(entityID) = component;
         }
@@ -88,7 +88,7 @@ namespace DCFApixels.DragonECS
     public abstract class TagComponentTemplate<T> : ComponentTemplateBase<T>
     where T : struct, IEcsTagComponent
     {
-        public override void Apply(int worldID, int entityID)
+        public override void Apply(short worldID, int entityID)
         {
             EcsWorld.GetPoolInstance<EcsTagPool<T>>(worldID).Set(entityID, true);
         }
diff --git a/src/EntityTemplate/Templates/MonoEntityTemplate.cs b/src/EntityTemplate/Templates/MonoEntityTemplate.cs
index 34a0903..35ac1ef 100644
--- a/src/EntityTemplate/Templates/MonoEntityTemplate.cs
+++ b/src/EntityTemplate/Templates/MonoEntityTemplate.cs
@@ -25,7 +25,7 @@ namespace DCFApixels.DragonECS
         #endregion
 
         #region Methods
-        public void Apply(int worldID, int entityID)
+        public void Apply(short worldID, int entityID)
         {
             foreach (var item in _components)
             {
diff --git a/src/EntityTemplate/Templates/ScriptableEntityTemplate.cs b/src/EntityTemplate/Templates/ScriptableEntityTemplate.cs
index e3c5253..198c990 100644
--- a/src/EntityTemplate/Templates/ScriptableEntityTemplate.cs
+++ b/src/EntityTemplate/Templates/ScriptableEntityTemplate.cs
@@ -24,7 +24,7 @@ namespace DCFApixels.DragonECS
         #endregion
 
         #region Methods
-        public void Apply(int worldID, int entityID)
+        public void Apply(short worldID, int entityID)
         {
             foreach (var item in _components)
             {