diff --git a/lualib/sproto.lua b/lualib/sproto.lua
index 757140ee..f5792099 100644
--- a/lualib/sproto.lua
+++ b/lualib/sproto.lua
@@ -107,6 +107,7 @@ local function queryproto(self, pname)
 
 	return v
 end
+sproto.queryproto = queryproto
 
 function sproto:exist_proto(pname)
 	local v = self.__pcache[pname]