diff --git a/pytorch3d/implicitron/tools/config.py b/pytorch3d/implicitron/tools/config.py
index 3289bd32b..d20759831 100644
--- a/pytorch3d/implicitron/tools/config.py
+++ b/pytorch3d/implicitron/tools/config.py
@@ -944,7 +944,7 @@ def init(self, *args, **kwargs) -> None:
         torch.nn.Module.__init__(self)
         getattr(self, _DATACLASS_INIT)(*args, **kwargs)
 
-    assert not hasattr(some_class, _DATACLASS_INIT)
+    assert _DATACLASS_INIT not in some_class.__dict__
 
     setattr(some_class, _DATACLASS_INIT, some_class.__init__)
     some_class.__init__ = init