diff --git a/src/etc/inc/system.inc b/src/etc/inc/system.inc
index 0c97b3932..225d4ed20 100644
--- a/src/etc/inc/system.inc
+++ b/src/etc/inc/system.inc
@@ -751,16 +751,17 @@ function system_routing_configure($verbose = false, $interface_map = null, $moni
 
             /* XXX some day we might want to convert to safer mwexecf() */
             $cmd = " -{$ipproto} {$blackhole} " . escapeshellarg($rtent['network']) . " ";
-            if (is_ipaddrv6($gatewayip) && $ipproto == 'inet') {
-                /* rfc5549: gateway protocol differs, so we need to define it as well */
-                $cmd .= ' -inet6 ';
-            }
-
             if (!empty($rtent['disabled'])) {
                 mwexec("/sbin/route delete {$cmd}", true);
             } else {
                 if (is_ipaddr($gatewayip)) {
                     mwexec("/sbin/route delete {$cmd}", true);
+
+                    if (ipproto == 'inet' && is_ipaddrv6($gatewayip)) {
+                        /* RFC 5549: gateway protocol differs */
+                        $cmd .= ' -inet6 ';
+                    }
+
                     if ($fargw) {
                         mwexecf('/sbin/route delete -%s %s -interface %s ', [$ipproto, $gatewayip, $interfacegw], true);
                         mwexecf('/sbin/route add -%s %s -interface %s', [$ipproto, $gatewayip, $interfacegw]);