diff --git a/src/Builtin/Worlds.cs b/src/Builtin/Worlds.cs
index 02bc174..d92e45e 100644
--- a/src/Builtin/Worlds.cs
+++ b/src/Builtin/Worlds.cs
@@ -1,23 +1,5 @@
 namespace DCFApixels.DragonECS
 {
-    public sealed class EcsDefaultWorld : EcsWorld<EcsDefaultWorld>
-    {
-        public EcsDefaultWorld() : base(null) { }
-        public EcsDefaultWorld(EcsPipeline pipeline) : base(pipeline) { }
-    }
-    public sealed class EcsPhysicsEventsWorld : EcsWorld<EcsPhysicsEventsWorld>
-    {
-        public EcsPhysicsEventsWorld() : base(null) { }
-        public EcsPhysicsEventsWorld(EcsPipeline pipeline) : base(pipeline) { }
-    }
-    public sealed class EcsEventWorld : EcsWorld<EcsEventWorld>
-    {
-        public EcsEventWorld() : base(null) { }
-        public EcsEventWorld(EcsPipeline pipeline) : base(pipeline) { }
-    }
-    public sealed class EcsUIWorld : EcsWorld<EcsUIWorld>
-    {
-        public EcsUIWorld() : base(null) { }
-        public EcsUIWorld(EcsPipeline pipeline) : base(pipeline) { }
-    }
+    public sealed class EcsDefaultWorld : EcsWorld<EcsDefaultWorld> { }
+    public sealed class EcsEventWorld : EcsWorld<EcsEventWorld> { }
 }