diff --git a/docs/security.md b/docs/security.md
index 754d0e8551..520c9a92bd 100644
--- a/docs/security.md
+++ b/docs/security.md
@@ -16,7 +16,7 @@ To change the SSH public key on an existing cluster:
 * `kops delete secret --name <clustername> sshpublickey admin`
 * `kops create secret --name <clustername> sshpublickey admin -i ~/.ssh/newkey.pub`
 * `kops update cluster --yes` to reconfigure the auto-scaling groups
-* `kops rolling-update --yes` to immediately roll all the machines so they have the new key (optional)
+* `kops rolling-update cluster --name <clustername> --yes` to immediately roll all the machines so they have the new key (optional)
 
 
 ## Kubernetes API