diff --git a/zaza/openstack/charm_tests/mysql/tests.py b/zaza/openstack/charm_tests/mysql/tests.py
index 830985b9d..ce9898d84 100644
--- a/zaza/openstack/charm_tests/mysql/tests.py
+++ b/zaza/openstack/charm_tests/mysql/tests.py
@@ -617,7 +617,7 @@ def _get_password_from_keystone_leader():
             action_params={}
         )
         usernames = yaml.safe_load(action.data['results']['usernames'])
-        logging.info("... usernames: %s", ', '.join(usernames))
+        logging.info("... usernames: %s", usernames)
         self.assertIn('keystone', usernames)
 
         # grab the password for keystone from the leader / to verify the change