diff --git a/planetstack/openstack_observer/steps/sync_controller_slices.py b/planetstack/openstack_observer/steps/sync_controller_slices.py
index 9e47669..0c24ae1 100644
--- a/planetstack/openstack_observer/steps/sync_controller_slices.py
+++ b/planetstack/openstack_observer/steps/sync_controller_slices.py
@@ -16,6 +16,7 @@
 class SyncControllerSlices(OpenStackSyncStep):
     provides=[Slice]
     requested_interval=0
+    observes=ControllerSlice
 
     def fetch_pending(self, deleted):
         if (deleted):