diff --git a/doc/openvpn_guide.md b/doc/openvpn_guide.md
index cd68c51..23ca627 100644
--- a/doc/openvpn_guide.md
+++ b/doc/openvpn_guide.md
@@ -18,6 +18,9 @@ assume server ip is 45.66.77.88
 
 #### client side config
 ```
+client
+dev tun100
+proto udp
 
 remote 127.0.0.1 3333
 resolv-retry infinite