diff --git a/openmptcprouter/files/etc/firewall.gre-tunnel b/openmptcprouter/files/etc/firewall.gre-tunnel
index 037f135f7..41b00e664 100644
--- a/openmptcprouter/files/etc/firewall.gre-tunnel
+++ b/openmptcprouter/files/etc/firewall.gre-tunnel
@@ -11,8 +11,10 @@ _setup_rules() {
 _setup_routes() {
 	config_get lookup $1 lookup
 	config_get gateway $1 gateway
-	intf=$(ifstatus | jsonfilter -e '@.l3_device' | tr -d "\n")
-	ip route replace default via $gateway dev $intf table $lookup
+	intf=$(ifstatus $1 | jsonfilter -e '@.l3_device' | tr -d "\n")
+	if [ -n "$lookup" ] && [ -n "$intf" ] && [ -n "$gateway" ]; then
+		ip route replace default via $gateway dev $intf table $lookup
+	fi
 }
 config_load network
 config_foreach _setup_rules interface