diff --git a/feed/mtkhnat_util/files/99-firewall b/feed/mtkhnat_util/files/99-firewall
index 9c72762..8c59b3f 100755
--- a/feed/mtkhnat_util/files/99-firewall
+++ b/feed/mtkhnat_util/files/99-firewall
@@ -1,3 +1,4 @@
+echo "iptables -I OUTPUT -t raw -p tcp --dport 1723 -j CT  --helper pptp" >> /etc/firewall.user
 echo "iptables -t mangle -A FORWARD -m dscp --dscp-class BE -j MARK --set-mark 0" >> /etc/firewall.user
 echo "iptables -t mangle -A FORWARD -m dscp --dscp-class CS2 -j MARK --set-mark 2" >> /etc/firewall.user
 echo "iptables -t mangle -A FORWARD -m dscp --dscp-class CS4 -j MARK --set-mark 4" >> /etc/firewall.user