fix

diff --git a/lib/sqlalchemy/orm/clsregistry.py b/lib/sqlalchemy/orm/clsregistry.py
index ed5e59bbfcf51f50956b110d6f07e3490db1e917..54353f3631b7394259008cfaf0810a7ba9dc7f58 100644 (file)
--- a/lib/sqlalchemy/orm/clsregistry.py
+++ b/lib/sqlalchemy/orm/clsregistry.py
@@ -72,7 +72,7 @@ def _add_class(
         # class already exists.
         existing = decl_class_registry[classname]
         if not isinstance(existing, _MultipleClassMarker):
-            existing = decl_class_registry[classname] = _MultipleClassMarker(
+            decl_class_registry[classname] = _MultipleClassMarker(
                 [cls, cast("Type[Any]", existing)]
             )
     else: