diff --git a/doc/topics/cloud/gce.rst b/doc/topics/cloud/gce.rst
index 5e9b07b4e7..0b6b4f9271 100644
--- a/doc/topics/cloud/gce.rst
+++ b/doc/topics/cloud/gce.rst
@@ -81,7 +81,7 @@ Set up the cloud config at ``/etc/salt/cloud``:
       gce-config:
         # Set up the Project name and Service Account authorization
         #
-        project: "your_project_name"
+        project: "your-project-name"
         service_account_email_address: "123-a5gt@developer.gserviceaccount.com"
         service_account_private_key: "/path/to/your/NEW.pem"
 
@@ -98,6 +98,9 @@ Set up the cloud config at ``/etc/salt/cloud``:
 
         provider: gce
 
+.. note::
+
+    The value provided for ``project`` must not contain underscores or spaces.
 
 
 Cloud Profiles