diff --git a/jitsi-auth-dovecot.sh b/jitsi-auth-dovecot.sh
index b1d1279..0a77946 100755
--- a/jitsi-auth-dovecot.sh
+++ b/jitsi-auth-dovecot.sh
@@ -274,6 +274,8 @@ else
 fi
 HOSTNAME="${FQHN_HOSTNAME%%.*}"
 
+[[ -z "$DOVECOT_AUTH_DOMAIN" ]] && DEFAULT_DOVECOT_AUTH_DOMAIN="$FQHN_HOSTNAME"
+
 
 _found=false
 while IFS='' read -r _line || [[ -n $_line ]] ; do