diff --git a/install_postfix_advanced.sh b/install_postfix_advanced.sh
index e437adf..f39adb5 100755
--- a/install_postfix_advanced.sh
+++ b/install_postfix_advanced.sh
@@ -451,6 +451,7 @@ if $IS_RELAY_HOST ; then
 
 else
    IS_SYMPA_LIST_SERVER=false
+   LISTEN_ON_ADDITIONAL_RELAY_PORT=false
 fi