diff --git a/aodh/tests/base.py b/aodh/tests/base.py
index 3569af28e..2a4942e0c 100644
--- a/aodh/tests/base.py
+++ b/aodh/tests/base.py
@@ -33,7 +33,7 @@ from aodh import messaging
 class BaseTestCase(base.BaseTestCase):
     def setup_messaging(self, conf, exchange=None):
         self.useFixture(oslo_messaging.conffixture.ConfFixture(conf))
-        conf.set_override("notification_driver", "messaging")
+        conf.set_override("notification_driver", ["messaging"])
         if not exchange:
             exchange = 'aodh'
         conf.set_override("control_exchange", exchange)