diff --git a/POSTINSTALL.md b/POSTINSTALL.md
index f747a42..0277f66 100644
--- a/POSTINSTALL.md
+++ b/POSTINSTALL.md
@@ -1,7 +1,6 @@
 Account ids are created with the username and the second level domain under which the
 app is installed e.g. `@$CLOUDRON-USERNAME@$CLOUDRON-APP-DOMAIN`.
 
-For federation to work, the second level domain (`$CLOUDRON-APP-DOMAIN`) has to be configured to serve up the
-`.well-known/matrix/server` URI. See the [federation docs](https://cloudron.io/documentation/apps/synapse/) on
-how to do this.
+For federation to work, the delegation URI `https://$CLOUDRON-APP-DOMAIN/.well-known/matrix/server`
+must be configured. See the [docs](https://docs.cloudron.io/apps/synapse/#post-installation) on how to do this.