diff --git a/TCP-Fast-Open.md b/TCP-Fast-Open.md
index 1c40814..89d62d1 100644
--- a/TCP-Fast-Open.md
+++ b/TCP-Fast-Open.md
@@ -1,10 +1,11 @@
 If both of your server and client are deployed on Linux 3.7+, you can turn on
 fast_open for lower latency.
 
-Turn on fast open on your OS temporarily:
+First set `fast_open` to `true` in your config.json.
+
+Then turn on fast open on your OS temporarily:
 
     echo 3 > /proc/sys/net/ipv4/tcp_fastopen
 
 To turn on fast open permanently, see [Optimizing Shadowsocks](https://github.com/clowwindy/shadowsocks/wiki/Optimizing-Shadowsocks).
 
-Then set `fast_open` to `true` in your config.json.