diff --git a/README.md b/README.md
index 3bd6c41..eb72080 100644
--- a/README.md
+++ b/README.md
@@ -52,6 +52,15 @@ To use the auth server, the following snippet needs to be added to the clients'
 auth-server=https://my-auth-server.example/
 ```
 
+Unless your clients are really offline, you also need to override the updater server to an
+invalid/unreachable address, otherwise the client will contact it with an invalid token on startup
+and prompt for a re-login:
+
+```ini
+[servers]
+updater-server=http://invalid.example
+```
+
 ### Running factoriauth
 
 TBD