diff --git a/development/README.md b/development/README.md
index a42cbf29..257f2f1a 100644
--- a/development/README.md
+++ b/development/README.md
@@ -97,6 +97,7 @@ You can create a new site with the following command:
 ```shell
 bench new-site sitename --no-mariadb-socket
 ```
+sitename MUST end with .localhost for trying deployments locally.
 
 for example: