diff --git a/lualib/skynet.lua b/lualib/skynet.lua
index abb568c8..16ad0c24 100644
--- a/lualib/skynet.lua
+++ b/lualib/skynet.lua
@@ -663,7 +663,7 @@ end
 
 -- Inject internal debug framework
 local debug = require "skynet.debug"
-debug(skynet, {
+debug.init(skynet, {
 	dispatch = skynet.dispatch_message,
 	suspend = suspend,
 })
diff --git a/lualib/skynet/debug.lua b/lualib/skynet/debug.lua
index 957a2588..8fb484de 100644
--- a/lualib/skynet/debug.lua
+++ b/lualib/skynet/debug.lua
@@ -1,96 +1,105 @@
 local table = table
-local extern_dbgcmd = {};
+local extern_dbgcmd = {}
 
-return function (skynet, export)
+local function init(skynet, export)
+	local internal_info_func
 
-local internal_info_func
-
-function skynet.info_func(func)
-	internal_info_func = func
-end
-
-local dbgcmd
-
-local function init_dbgcmd()
-dbgcmd = extern_dbgcmd
-
-function dbgcmd.MEM()
-	local kb, bytes = collectgarbage "count"
-	skynet.ret(skynet.pack(kb,bytes))
-end
-
-function dbgcmd.GC()
-	collectgarbage "collect"
-end
-
-function dbgcmd.STAT()
-	local stat = {}
-	stat.mqlen = skynet.mqlen()
-	stat.task = skynet.task()
-	skynet.ret(skynet.pack(stat))
-end
-
-function dbgcmd.TASK()
-	local task = {}
-	skynet.task(task)
-	skynet.ret(skynet.pack(task))
-end
-
-function dbgcmd.INFO(...)
-	if internal_info_func then
-		skynet.ret(skynet.pack(internal_info_func(...)))
-	else
-		skynet.ret(skynet.pack(nil))
+	function skynet.info_func(func)
+		internal_info_func = func
 	end
+
+	local dbgcmd
+
+	local function init_dbgcmd()
+		dbgcmd = {}
+
+		function dbgcmd.MEM()
+			local kb, bytes = collectgarbage "count"
+			skynet.ret(skynet.pack(kb,bytes))
+		end
+
+		function dbgcmd.GC()
+
+			collectgarbage "collect"
+		end
+
+		function dbgcmd.STAT()
+			local stat = {}
+			stat.mqlen = skynet.mqlen()
+			stat.task = skynet.task()
+			skynet.ret(skynet.pack(stat))
+		end
+
+		function dbgcmd.TASK()
+			local task = {}
+			skynet.task(task)
+			skynet.ret(skynet.pack(task))
+		end
+
+		function dbgcmd.INFO(...)
+			if internal_info_func then
+				skynet.ret(skynet.pack(internal_info_func(...)))
+			else
+				skynet.ret(skynet.pack(nil))
+			end
+		end
+
+		function dbgcmd.EXIT()
+			skynet.exit()
+		end
+
+		function dbgcmd.RUN(source, filename)
+			local inject = require "skynet.inject"
+			local output = inject(skynet, source, filename , export.dispatch, skynet.register_protocol)
+			collectgarbage "collect"
+			skynet.ret(skynet.pack(table.concat(output, "\n")))
+		end
+
+		function dbgcmd.TERM(service)
+			skynet.term(service)
+		end
+
+		function dbgcmd.REMOTEDEBUG(...)
+			local remotedebug = require "skynet.remotedebug"
+			remotedebug.start(export, ...)
+		end
+
+		function dbgcmd.SUPPORT(pname)
+			return skynet.ret(skynet.pack(skynet.dispatch(pname) ~= nil))
+		end
+
+		function dbgcmd.PING()
+			return skynet.ret()
+		end
+
+		function dbgcmd.LINK()
+			-- no return, raise error when exit
+		end
+
+		return dbgcmd
+	end -- function init_dbgcmd
+
+	local function _debug_dispatch(session, address, cmd, ...)
+		dbgcmd = dbgcmd or init_dbgcmd() -- lazy init dbgcmd
+		local f = dbgcmd[cmd] or extern_dbgcmd[cmd]
+		assert(f, cmd)
+		f(...)
+	end
+
+	skynet.register_protocol {
+		name = "debug",
+		id = assert(skynet.PTYPE_DEBUG),
+		pack = assert(skynet.pack),
+		unpack = assert(skynet.unpack),
+		dispatch = _debug_dispatch,
+	}
 end
 
-function dbgcmd.EXIT()
-	skynet.exit()
+local function reg_debugcmd(name, fn)
+	extern_dbgcmd[name] = fn
 end
 
-function dbgcmd.RUN(source, filename)
-	local inject = require "skynet.inject"
-	local output = inject(skynet, source, filename , export.dispatch, skynet.register_protocol)
-	collectgarbage "collect"
-	skynet.ret(skynet.pack(table.concat(output, "\n")))
-end
-
-function dbgcmd.TERM(service)
-	skynet.term(service)
-end
-
-function dbgcmd.REMOTEDEBUG(...)
-	local remotedebug = require "skynet.remotedebug"
-	remotedebug.start(export, ...)
-end
-
-function dbgcmd.SUPPORT(pname)
-	return skynet.ret(skynet.pack(skynet.dispatch(pname) ~= nil))
-end
-
-function dbgcmd.PING()
-	return skynet.ret()
-end
-
-function dbgcmd.LINK()
-	-- no return, raise error when exit
-end
-
-return dbgcmd
-end -- function init_dbgcmd
-
-local function _debug_dispatch(session, address, cmd, ...)
-	local f = (dbgcmd or init_dbgcmd())[cmd]	-- lazy init dbgcmd
-	assert(f, cmd)
-	f(...)
-end
-
-skynet.register_protocol {
-	name = "debug",
-	id = assert(skynet.PTYPE_DEBUG),
-	pack = assert(skynet.pack),
-	unpack = assert(skynet.unpack),
-	dispatch = _debug_dispatch,
+return {
+	init = init,
+	reg_debugcmd = reg_debugcmd,
 }
-
-end