diff --git a/roles/mirrormanager/backend/files/backend.cron b/roles/mirrormanager/backend/files/backend.cron
index 71f82b01f2..40c44f34f4 100644
--- a/roles/mirrormanager/backend/files/backend.cron
+++ b/roles/mirrormanager/backend/files/backend.cron
@@ -5,7 +5,7 @@ MAILTO=root
 
 # update master directory list
 # logs sent to /var/log/mirrormanager/umdl.log by default
-0 */2 * * * root /usr/bin/mm2_update-master-directory-list
+0 */2 * * * root /usr/local/bin/lock-wrapper umdl /usr/bin/mm2_update-master-directory-list
 
 # Sync netblocks list once a day
 30 0 * * * root cd /usr/share/mirrormanager2 && /usr/bin/mm2_get_global_netblocks /var/lib/mirrormanager/global_netblocks.txt