diff --git a/docs/14-cleanup.md b/docs/14-cleanup.md
index dc97a3a..2fe430b 100644
--- a/docs/14-cleanup.md
+++ b/docs/14-cleanup.md
@@ -9,7 +9,7 @@ Delete the controller and worker compute instances:
 ```
 gcloud -q compute instances delete \
   controller-0 controller-1 controller-2 \
-  worker-0 worker-1 worker-2
+  worker-0 worker-1 worker-2 --zone us-west1-c
 ```
 
 ## Networking