diff --git a/docs/admin/config-cheat-sheet.md b/docs/admin/config-cheat-sheet.md
index ee402224..1b02a47a 100644
--- a/docs/admin/config-cheat-sheet.md
+++ b/docs/admin/config-cheat-sheet.md
@@ -499,6 +499,7 @@ And the following unique queues:
 
 - `DEFAULT_EMAIL_NOTIFICATIONS`: **enabled**: Default configuration for email notifications for users (user configurable). Options: enabled, onmention, disabled
 - `DISABLE_REGULAR_ORG_CREATION`: **false**: Disallow regular (non-admin) users from creating organizations.
+- `NOTIFY_NEW_SIGN_UPS`: **false**: enable email notifications to instance admins on new user sign-up.
 
 ## Security (`security`)