diff --git a/README.md b/README.md
index ccea727..e361118 100644
--- a/README.md
+++ b/README.md
@@ -152,6 +152,7 @@ Variable | Description | Default value
 `XMPP_AUTH_DOMAIN` | Internal XMPP domain for authenticated services | auth.meet.jitsi
 `XMPP_MUC_DOMAIN` | XMPP domain for the MUC | muc.meet.jitsi
 `XMPP_INTERNAL_MUC_DOMAIN` | XMPP domain for the internal MUC | internal-muc.meet.jitsi
+`XMPP_GUEST_DOMAIN` | XMPP domain for unauthenticated users | guest.meet.jitsi
 `JICOFO_COMPONENT_SECRET` | XMPP component password for Jicofo | s3cr37
 `JICOFO_AUTH_USER` | XMPP user for Jicofo client connections | focus
 `JICOFO_AUTH_PASSWORD` | XMPP password for Jicofo client connections | passw0rd