diff --git a/shadowsocks.sh b/shadowsocks.sh
index 282d285..b5c7fa8 100644
--- a/shadowsocks.sh
+++ b/shadowsocks.sh
@@ -107,7 +107,7 @@ EOF
 function iptables_set(){
     /sbin/service iptables status 1>/dev/null 2>&1
     if [ $? -eq 0 ]; then
-        /etc/init.d/iptables status | grep '8989' | grep 'ACCEPT'
+        /etc/init.d/iptables status | grep '8989' | grep 'ACCEPT' >/dev/null 2>&1
         if [ $? -ne 0 ]; then
             /sbin/iptables -A INPUT -m state --state NEW -m tcp -p tcp --dport 8989 -j ACCEPT
             /etc/rc.d/init.d/iptables save