diff --git a/nova/tests/unit/api/openstack/compute/test_instance_usage_audit_log.py b/nova/tests/unit/api/openstack/compute/test_instance_usage_audit_log.py
index 9b1ae9a759f7..46d0274b31a8 100644
--- a/nova/tests/unit/api/openstack/compute/test_instance_usage_audit_log.py
+++ b/nova/tests/unit/api/openstack/compute/test_instance_usage_audit_log.py
@@ -23,7 +23,6 @@ from nova import exception
 from nova import test
 from nova.tests.unit.api.openstack import fakes
 from nova.tests.unit.objects import test_service
-from nova import utils
 
 
 service_base = test_service.fake_service
@@ -121,8 +120,8 @@ class InstanceUsageAuditLogTestV21(test.NoDBTestCase):
             self.assertIsNone(disabled)
             return TEST_COMPUTE_SERVICES
 
-        self.stubs.Set(utils, 'last_completed_audit_period',
-                            fake_last_completed_audit_period)
+        self.stub_out('nova.utils.last_completed_audit_period',
+                      fake_last_completed_audit_period)
         self.stub_out('nova.db.service_get_all', fake_service_get_all)
         self.stub_out('nova.db.task_log_get_all', fake_task_log_get_all)