diff --git a/docs/deployment/builders/dockerfiles.md b/docs/deployment/builders/dockerfiles.md
index ce48be6c1..d22d9243d 100644
--- a/docs/deployment/builders/dockerfiles.md
+++ b/docs/deployment/builders/dockerfiles.md
@@ -196,7 +196,7 @@ ENTRYPOINT ["node"]
 You can do:
 
 ```shell
-dokku ps:set node-js-app dockerfile-start-cmd "--harmony server.js"
+dokku ps:set node-js-app dockerfile-start-cmd -- "--harmony server.js"
 ```
 
 To tell Docker what to run. Pass an empty value to clear the override: