diff --git a/charms_openstack/test_mocks.py b/charms_openstack/test_mocks.py
index 8b7aef9..566dd65 100644
--- a/charms_openstack/test_mocks.py
+++ b/charms_openstack/test_mocks.py
@@ -62,4 +62,5 @@ def mock_charmhelpers():
         'pike',
         'queens',
         'rocky',
+        'train',
     )