diff --git a/src/www/guiconfig.inc b/src/www/guiconfig.inc
index f9701d36f..881674c28 100644
--- a/src/www/guiconfig.inc
+++ b/src/www/guiconfig.inc
@@ -408,7 +408,7 @@ function pconfig_to_address(&$adr, $padr, $pmask, $pnot=false, $pbeginport=0, $p
     if (is_alias($pbeginport)) {
         $adr['port'] = $pbeginport;
     } elseif (($pbeginport != 0) && ($pbeginport != "any")) {
-        if ($pbeginport != $pendport) {
+        if ($pbeginport != $pendport && !empty($pendport)) {
             $adr['port'] = $pbeginport . "-" . $pendport;
         } else {
             $adr['port'] = $pbeginport;