diff --git a/exts/omni.ext.mobility_gen/omni/ext/mobility_gen/scene_builders.py b/exts/omni.ext.mobility_gen/omni/ext/mobility_gen/scene_builders.py
index aa983d9..e462b8e 100644
--- a/exts/omni.ext.mobility_gen/omni/ext/mobility_gen/scene_builders.py
+++ b/exts/omni.ext.mobility_gen/omni/ext/mobility_gen/scene_builders.py
@@ -82,6 +82,7 @@ def build(cls, prim_path: str):
             )
 
 
+@SCENE_BUILDERS.register()
 @SCENE_BUILDERS.register()
 class RandomCubeSceneSmall(RandomCubeScene):
     num_cubes: int = 20