diff --git a/README.md b/README.md
index 8a2fe7dcf..625131ecb 100644
--- a/README.md
+++ b/README.md
@@ -79,7 +79,7 @@ web:
 
     FROM orchardup/rails
     ADD . /code
-    CMD: bundle exec rackup
+    RUN bundle exec rackup
 
 
 ### Communicating between containers