diff --git a/lualib/sproto.lua b/lualib/sproto.lua
index 9c6524b2..f6338008 100644
--- a/lualib/sproto.lua
+++ b/lualib/sproto.lua
@@ -197,6 +197,7 @@ function host:dispatch(...)
 	local bin = core.unpack(...)
 	header_tmp.type = nil
 	header_tmp.session = nil
+	header_tmp.ud = nil
 	local header, size = core.decode(self.__package, bin, header_tmp)
 	local content = bin:sub(size + 1)
 	if header.type then
@@ -207,9 +208,9 @@ function host:dispatch(...)
 			result = core.decode(proto.request, content)
 		end
 		if header_tmp.session then
-			return "REQUEST", proto.name, result, gen_response(self, proto.response, header_tmp.session)
+			return "REQUEST", proto.name, result, gen_response(self, proto.response, header_tmp.session), header.ud
 		else
-			return "REQUEST", proto.name, result
+			return "REQUEST", proto.name, result, nil, header.ud
 		end
 	else
 		-- response
@@ -217,10 +218,10 @@ function host:dispatch(...)
 		local response = assert(self.__session[session], "Unknown session")
 		self.__session[session] = nil
 		if response == true then
-			return "RESPONSE", session
+			return "RESPONSE", session, nil, header.ud
 		else
 			local result = core.decode(response, content)
-			return "RESPONSE", session, result
+			return "RESPONSE", session, result, header.ud
 		end
 	end
 end