diff --git a/src/www/interfaces_gif_edit.php b/src/www/interfaces_gif_edit.php
index a1f69bc65a5..51ccc86110d 100644
--- a/src/www/interfaces_gif_edit.php
+++ b/src/www/interfaces_gif_edit.php
@@ -143,7 +143,7 @@ interface_configure(false, $confif);
diff --git a/src/www/interfaces_gre_edit.php b/src/www/interfaces_gre_edit.php
index a642d8b29f0..8e63c26f146 100644
--- a/src/www/interfaces_gre_edit.php
+++ b/src/www/interfaces_gre_edit.php
@@ -113,7 +113,7 @@ interface_configure(false, $confif);
diff --git a/src/www/javascript/opnsense_legacy.js b/src/www/javascript/opnsense_legacy.js
index f3b6948d664..9bf3ac655bb 100644
--- a/src/www/javascript/opnsense_legacy.js
+++ b/src/www/javascript/opnsense_legacy.js
@@ -35,7 +35,7 @@
* @param classname: classname to hook on to, select list of netmasks
* @param data_id: data field reference to network input field
*/
-function hook_ipv4v6(classname, data_id)
+function hook_ipv4v6(classname, data_id, prefixlen)
{
$("select."+classname).each(function(){
var selectlist_id = $(this).attr('id');
@@ -49,7 +49,7 @@ function hook_ipv4v6(classname, data_id)
$("#"+selectlist_id+' option[value=' + i + ']').show()
}
if ((type === undefined && val == '') || type === '4') {
- net = '64';
+ net = prefixlen == undefined ? '64' : prefixlen;
}
type = '6';
} else {