diff --git a/mistral/tests/unit/api/v2/test_actions.py b/mistral/tests/unit/api/v2/test_actions.py
index 17be0764b..451ec5824 100644
--- a/mistral/tests/unit/api/v2/test_actions.py
+++ b/mistral/tests/unit/api/v2/test_actions.py
@@ -161,7 +161,7 @@ class TestActionsController(base.FunctionalTest):
         self.assertEqual(resp.status_int, 201)
         self.assertEqual({"actions": [ACTION]}, resp.json)
 
-        mock_mtd.assert_called_once()
+        self.assertEqual(1, mock_mtd.call_count)
 
         values = mock_mtd.call_args[0][0]
 
diff --git a/mistral/tests/unit/api/v2/test_cron_triggers.py b/mistral/tests/unit/api/v2/test_cron_triggers.py
index 828b11542..4d2f138ac 100644
--- a/mistral/tests/unit/api/v2/test_cron_triggers.py
+++ b/mistral/tests/unit/api/v2/test_cron_triggers.py
@@ -91,7 +91,7 @@ class TestCronTriggerController(base.FunctionalTest):
         self.assertEqual(resp.status_int, 201)
         self.assertDictEqual(TRIGGER, resp.json)
 
-        mock_mtd.assert_called_once()
+        self.assertEqual(1, mock_mtd.call_count)
 
         values = mock_mtd.call_args[0][0]
 
diff --git a/mistral/tests/unit/api/v2/test_workflows.py b/mistral/tests/unit/api/v2/test_workflows.py
index 11c7c2e48..de311f92a 100644
--- a/mistral/tests/unit/api/v2/test_workflows.py
+++ b/mistral/tests/unit/api/v2/test_workflows.py
@@ -234,7 +234,7 @@ class TestWorkflowsController(base.FunctionalTest):
         self.assertEqual(resp.status_int, 201)
         self.assertDictEqual({'workflows': [WF]}, resp.json)
 
-        mock_mtd.assert_called_once()
+        self.assertEqual(1, mock_mtd.call_count)
 
         spec = mock_mtd.call_args[0][0]['spec']
 
diff --git a/mistral/tests/unit/engine/test_direct_workflow.py b/mistral/tests/unit/engine/test_direct_workflow.py
index 021e34958..1b9eecd1f 100644
--- a/mistral/tests/unit/engine/test_direct_workflow.py
+++ b/mistral/tests/unit/engine/test_direct_workflow.py
@@ -204,7 +204,8 @@ class DirectWorkflowEngineTest(base.EngineTestCase):
                 exc.InvalidActionException,
                 self.engine.start_workflow, 'wf', None)
 
-            mock_fw.assert_called_once()
+            self.assertEqual(1, mock_fw.call_count)
+
             self.assertTrue(
                 issubclass(
                     type(mock_fw.call_args[0][1]),
@@ -253,7 +254,7 @@ class DirectWorkflowEngineTest(base.EngineTestCase):
                 self.engine.start_workflow, 'wf', None
             )
 
-            mock_fw.assert_called_once()
+            self.assertEqual(1, mock_fw.call_count)
             self.assertTrue(
                 issubclass(
                     type(mock_fw.call_args[0][1]),