diff --git a/mail/postfix/files/pkg-install.in b/mail/postfix/files/pkg-install.in
index 1871094..e34031a 100644
--- a/mail/postfix/files/pkg-install.in
+++ b/mail/postfix/files/pkg-install.in
@@ -36,7 +36,7 @@ ask() {
 
       question=$1
       default=$2
-      if [ -z "${PACKAGE_BUILDING}" -a "${BATCH}" = "no" ]; then
+      if [ -z "${PACKAGE_BUILDING}" -a "${BATCH}" = "no" -a -t 0 ]; then
 	      read -p "${question} [${default}]? " answer
       fi
       if [ -z "${answer}" ]; then