diff --git a/usr/local/www/firewall_virtual_ip.php b/usr/local/www/firewall_virtual_ip.php
index 784d1bf0f7..3a3cb3df07 100755
--- a/usr/local/www/firewall_virtual_ip.php
+++ b/usr/local/www/firewall_virtual_ip.php
@@ -110,11 +110,13 @@ if ($_GET['act'] == "del") {
 		if (is_ipaddrv6($a_vip[$_GET['id']]['subnet'])) {
 			$is_ipv6 = true;
 			$subnet = gen_subnetv6($a_vip[$_GET['id']]['subnet'], $a_vip[$_GET['id']]['subnet_bits']);
-			$if_subnet = gen_subnetv6(get_interface_ipv6($a_vip[$_GET['id']]['interface']), get_interface_subnetv6($a_vip[$_GET['id']]['interface']));
+			$if_subnet_bits = get_interface_subnetv6($a_vip[$_GET['id']]['interface']);
+			$if_subnet = gen_subnetv6(get_interface_ipv6($a_vip[$_GET['id']]['interface']), $if_subnet_bits);
 		} else {
 			$is_ipv6 = false;
 			$subnet = gen_subnet($a_vip[$_GET['id']]['subnet'], $a_vip[$_GET['id']]['subnet_bits']);
-			$if_subnet = gen_subnet(get_interface_ip($a_vip[$_GET['id']]['interface']), get_interface_subnet($a_vip[$_GET['id']]['interface']));
+			$if_subnet_bits = get_interface_subnet($a_vip[$_GET['id']]['interface']);
+			$if_subnet = gen_subnet(get_interface_ip($a_vip[$_GET['id']]['interface']), $if_subnet_bits);
 		}
 
 		$subnet .= "/" . $a_vip[$_GET['id']]['subnet_bits'];