diff --git a/sdk/basyx/aas/adapter/json/json_deserialization.py b/sdk/basyx/aas/adapter/json/json_deserialization.py
index 7e0c39ce0..324ff6fa7 100644
--- a/sdk/basyx/aas/adapter/json/json_deserialization.py
+++ b/sdk/basyx/aas/adapter/json/json_deserialization.py
@@ -340,10 +340,11 @@ def _construct_model_reference(cls, dct: Dict[str, object], type_: Type[T], obje
         if reference_type is not model.ModelReference:
             raise ValueError(f"Expected a reference of type {model.ModelReference}, got {reference_type}!")
         keys = [cls._construct_key(key_data) for key_data in _get_ts(dct, "keys", list)]
-        if keys and not issubclass(KEY_TYPES_CLASSES_INVERSE.get(keys[-1].type, type(None)), type_):
+        last_key_type = KEY_TYPES_CLASSES_INVERSE.get(keys[-1].type, type(None))
+        if keys and not issubclass(last_key_type, type_):
             logger.warning("type %s of last key of reference to %s does not match reference type %s",
                            keys[-1].type.name, " / ".join(str(k) for k in keys), type_.__name__)
-        return object_class(tuple(keys), type_, cls._construct_reference(_get_ts(dct, 'referredSemanticId', dict))
+        return object_class(tuple(keys), last_key_type, cls._construct_reference(_get_ts(dct, 'referredSemanticId', dict))
                             if 'referredSemanticId' in dct else None)
 
     @classmethod