diff --git a/udp2raw-openvpn-config-guide.md b/udp2raw-openvpn-config-guide.md
index 928ecd6..6994273 100644
--- a/udp2raw-openvpn-config-guide.md
+++ b/udp2raw-openvpn-config-guide.md
@@ -45,7 +45,7 @@ comp-lzo no   #this option is deprecated since openvpn2.4. For 2.4 and above, us
 cipher none      ##### disable openvpn 's cipher and auth for maxmized peformance. 
 auth none        ##### you can enable openvpn's cipher and auth,if you dont care about peformance,or you dont trust udp2raw 's encryption
 
-fragment 1200       ##### very important    you can turn it up a bit. but,the lower the safer
+fragment 1200       ##### very important    it's a conservative value, you can turn it up a bit
 mssfix 1200         ##### very important
 
 sndbuf 2000000      ##### important