diff --git a/docs/deploying.md b/docs/deploying.md
index bf007148..a6a8e386 100644
--- a/docs/deploying.md
+++ b/docs/deploying.md
@@ -107,6 +107,7 @@ Make sure you stopped your registry from the previous step, then start it again:
 
     docker run -d -p 5000:5000 --restart=always --name registry \
       -v `pwd`/auth:/auth \
+      -e "REGISTRY_AUTH=htpasswd" \
       -e "REGISTRY_AUTH_HTPASSWD_REALM=Registry Realm" \
       -e REGISTRY_AUTH_HTPASSWD_PATH=/auth/htpasswd \
       -v `pwd`/certs:/certs \