diff --git a/neutron/services/qos/qos_plugin.py b/neutron/services/qos/qos_plugin.py
index 0da98691ceb..8b61fbceab3 100644
--- a/neutron/services/qos/qos_plugin.py
+++ b/neutron/services/qos/qos_plugin.py
@@ -186,7 +186,7 @@ class QoSPlugin(qos.QoSPluginBase):
         """
         policy_data = policy['policy']
         with db_api.context_manager.writer.using(context):
-            policy_obj = policy_object.QosPolicy(context, id=policy_id)
+            policy_obj = self._get_policy_obj(context, policy_id)
             policy_obj.update_fields(policy_data, reset_changes=True)
             policy_obj.update()
             self.driver_manager.call(qos_consts.UPDATE_POLICY_PRECOMMIT,
diff --git a/neutron/tests/fullstack/test_qos.py b/neutron/tests/fullstack/test_qos.py
index 1f5d2376b73..039d4945be7 100644
--- a/neutron/tests/fullstack/test_qos.py
+++ b/neutron/tests/fullstack/test_qos.py
@@ -330,7 +330,7 @@ class TestQoSPolicyIsDefault(base.BaseFullStackTestCase):
             qos_policy = self._create_qos_policy(project_id, True)
             self.assertTrue(qos_policy['is_default'])
             qos_policy = self._update_qos_policy(qos_policy['id'], False)
-            self.assertTrue(qos_policy['policy']['is_default'])
+            self.assertFalse(qos_policy['policy']['is_default'])
 
     def test_update_default_status_conflict(self):
         project_id = uuidutils.generate_uuid()
diff --git a/neutron/tests/unit/services/qos/test_qos_plugin.py b/neutron/tests/unit/services/qos/test_qos_plugin.py
index 1dfa37c283e..5b0529383f6 100644
--- a/neutron/tests/unit/services/qos/test_qos_plugin.py
+++ b/neutron/tests/unit/services/qos/test_qos_plugin.py
@@ -359,12 +359,14 @@ class TestQosPlugin(base.BaseQosTestCase):
 
         QosMocked.assert_called_once_with(self.ctxt, **policy_details)
 
+    @mock.patch.object(policy_object.QosPolicy, "get_object")
     @mock.patch(
         'neutron.objects.rbac_db.RbacNeutronDbObjectMixin'
         '.create_rbac_policy')
     @mock.patch.object(policy_object.QosPolicy, 'update')
     def test_update_policy(self, mock_qos_policy_update,
-                           mock_create_rbac_policy):
+                           mock_create_rbac_policy, mock_qos_policy_get):
+        mock_qos_policy_get.return_value = self.policy
         mock_manager = mock.Mock()
         mock_manager.attach_mock(mock_qos_policy_update, 'update')
         mock_manager.attach_mock(self.qos_plugin.driver_manager, 'driver')