diff --git a/tests/mocklib/keystoneclient/v3/tokens.py b/tests/mocklib/keystoneclient/v3/tokens.py
index 9c641937e..46870bbb2 100644
--- a/tests/mocklib/keystoneclient/v3/tokens.py
+++ b/tests/mocklib/keystoneclient/v3/tokens.py
@@ -1,8 +1,9 @@
 from unittest import mock
 
 
-class TokenManager(mock.Mock):
+class TokenManager:
+    validate = mock.Mock(name='validate')
+    validate.return_value = {'expires_at': '3022.07.04 00:00 CEST'}
+
     def __init__(self, *argv, **kwarg):
-        super().__init__(*argv, **kwarg)
-        self.validate = mock.Mock(name='validate')
-        self.validate.return_value = {'expires_at': '3022.07.04 00:00 CEST'}
+        pass