diff --git a/stgpytools/types/utils.py b/stgpytools/types/utils.py
index da301be..1818a35 100644
--- a/stgpytools/types/utils.py
+++ b/stgpytools/types/utils.py
@@ -269,7 +269,7 @@ def __get__(
         def _wrapper(self: T, *_args: P.args, **kwargs: P.kwargs) -> R:
             assert this.signature
 
-            if not isinstance(self, class_type):  # type: ignore
+            if class_obj and not isinstance(self, class_type):  # type: ignore
                 _args = (self, *_args)  # type: ignore
                 self = class_obj  # type: ignore