diff --git a/shadowsocks.sh b/shadowsocks.sh
index 9951ddb..3ac714b 100644
--- a/shadowsocks.sh
+++ b/shadowsocks.sh
@@ -316,10 +316,10 @@ function install_shadowsocks(){
     pre_install
     download_files
     config_shadowsocks
-    install_ss
     if [ "$OS" == 'CentOS' ]; then
         firewall_set
     fi
+    install_ss
 }
 
 # Initialization step