diff --git a/oslo_versionedobjects/fixture.py b/oslo_versionedobjects/fixture.py
index bef5657..5250871 100644
--- a/oslo_versionedobjects/fixture.py
+++ b/oslo_versionedobjects/fixture.py
@@ -101,10 +101,9 @@ class FakeIndirectionAPI(base.VersionedObjectIndirectionAPI):
         args, kwargs = self._canonicalize_args(context, args, kwargs)
         objver = object_versions[objname]
         cls = base.VersionedObject.obj_class_from_name(objname, objver)
-        with mock.patch('oslo_versionedobjects.base.VersionedObject.'
-                        'indirection_api', new=None):
+        with mock.patch.object(cls, 'indirection_api', new=None):
             result = getattr(cls, objmethod)(context, *args, **kwargs)
-        return (base.VersionedObject.obj_from_primitive(
+        return (cls.obj_from_primitive(
             result.obj_to_primitive(target_version=objver),
             context=context)
             if isinstance(result, base.VersionedObject) else result)