diff --git a/docker/update_api.sh b/docker/update_api.sh
index b0dea7d01795b884c9db967851a1e79f947268c1..1c35b11656b55926e4de1022afb8d8bbab91c7a3 100755
--- a/docker/update_api.sh
+++ b/docker/update_api.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-SERVICE_NAME=${1?"Usage: docker_update <SERVICE_NAME>"}
+SERVICE_NAME=${1?"Usage: docker_update [trefle|trefle-old]"}
 
 date >> update.log
 echo $* >> update.log