diff --git a/README.md b/README.md
index ceaa4d56..d438b558 100644
--- a/README.md
+++ b/README.md
@@ -23,16 +23,14 @@ Run these in different console
 
 ```
 ./skynet examples/config	# Launch first skynet node  (Gate server) and a skynet-master (see config for standalone option)
-lua examples/client.lua 	# Launch a client, and try to input some words.
+./3rd/lua/lua examples/client.lua 	# Launch a client, and try to input hello.
 ```
 
 ## About Lua
 
-Skynet put a modified version of lua 5.2.3 in 3rd/lua , it can share proto type between lua state (http://lua-users.org/lists/lua-l/2014-03/msg00489.html) .
+Skynet now use lua 5.3.0-rc3 , http://www.lua.org/work/lua-5.3.0-rc3.tar.gz
 
-Each lua file only load once and cache it in memory during skynet start . so if you want to reflush the cache , call skynet.cache.clear() .
-
-You can also use the offical lua version , edit the makefile by yourself .
+You can also use the other offical lua version , edit the makefile by yourself .
 
 ## How To (in Chinese)
 
diff --git a/examples/client.lua b/examples/client.lua
index e9efc160..a17b1926 100644
--- a/examples/client.lua
+++ b/examples/client.lua
@@ -1,8 +1,11 @@
 package.cpath = "luaclib/?.so"
 package.path = "lualib/?.lua;examples/?.lua"
 
+if _VERSION ~= "Lua 5.3" then
+	error "Use lua 5.3"
+end
+
 local socket = require "clientsocket"
-local bit32 = require "bit32"
 local proto = require "proto"
 local sproto = require "sproto"
 
@@ -13,10 +16,7 @@ local fd = assert(socket.connect("127.0.0.1", 8888))
 
 local function send_package(fd, pack)
 	local size = #pack
-	local package = string.char(bit32.extract(size,8,8)) ..
-		string.char(bit32.extract(size,0,8))..
-		pack
-
+	local package = string.pack(">s2", pack)
 	socket.send(fd, package)
 end