diff --git a/novaclient/tests/utils.py b/novaclient/tests/utils.py
index a257ac1fa..ab1ddcd18 100644
--- a/novaclient/tests/utils.py
+++ b/novaclient/tests/utils.py
@@ -14,6 +14,7 @@
 import os
 
 import fixtures
+import mock
 from oslo.serialization import jsonutils
 import requests
 from requests_mock.contrib import fixture as requests_mock_fixture
@@ -26,6 +27,29 @@ AUTH_URL_V1 = "http://localhost:5002/auth_url/v1.0"
 AUTH_URL_V2 = "http://localhost:5002/auth_url/v2.0"
 
 
+def _patch_mock_to_raise_for_invalid_assert_calls():
+    def raise_for_invalid_assert_calls(wrapped):
+        def wrapper(_self, name):
+            valid_asserts = [
+                'assert_called_with',
+                'assert_called_once_with',
+                'assert_has_calls',
+                'assert_any_calls']
+
+            if name.startswith('assert') and name not in valid_asserts:
+                raise AttributeError('%s is not a valid mock assert method'
+                                     % name)
+
+            return wrapped(_self, name)
+        return wrapper
+    mock.Mock.__getattr__ = raise_for_invalid_assert_calls(
+        mock.Mock.__getattr__)
+
+# NOTE(gibi): needs to be called only once at import time
+# to patch the mock lib
+_patch_mock_to_raise_for_invalid_assert_calls()
+
+
 class TestCase(testtools.TestCase):
     TEST_REQUEST_BASE = {
         'verify': True,
diff --git a/novaclient/tests/v1_1/test_auth.py b/novaclient/tests/v1_1/test_auth.py
index 6355b3245..97e402798 100644
--- a/novaclient/tests/v1_1/test_auth.py
+++ b/novaclient/tests/v1_1/test_auth.py
@@ -369,8 +369,8 @@ class AuthenticationTests(utils.TestCase):
         @mock.patch.object(http_client, 'authenticate')
         def test_auth_call(m):
             http_client.get('/')
-            m.assert_called()
-            mock_request.assert_called()
+            self.assertTrue(m.called)
+            self.assertTrue(mock_request.called)
 
         test_auth_call()
 
@@ -381,6 +381,6 @@ class AuthenticationTests(utils.TestCase):
         @mock.patch.object(cs.client, 'authenticate')
         def test_auth_call(m):
             cs.authenticate()
-            m.assert_called()
+            self.assertTrue(m.called)
 
         test_auth_call()