diff --git a/3rd/lua/lapi.c b/3rd/lua/lapi.c
index ffea5e53..0422cbc3 100644
--- a/3rd/lua/lapi.c
+++ b/3rd/lua/lapi.c
@@ -858,6 +858,8 @@ LUA_API int lua_setmetatable (lua_State *L, int objindex) {
   }
   switch (ttnov(obj)) {
     case LUA_TTABLE: {
+      if (isshared(hvalue(obj)))
+        luaG_runerror(L, "can't setmetatable to shared table");
       hvalue(obj)->metatable = mt;
       if (mt) {
         luaC_objbarrier(L, gcvalue(obj), mt);
@@ -1041,10 +1043,8 @@ LUA_API void lua_clonefunction (lua_State *L, const void * fp) {
 }
 
 LUA_API void lua_sharefunction (lua_State *L, int index) {
-  if (!lua_isfunction(L,index) || lua_iscfunction(L,index)) {
-    lua_pushstring(L, "Only Lua function can share");
-    lua_error(L);
-  }
+  if (!lua_isfunction(L,index) || lua_iscfunction(L,index))
+    luaG_runerror(L, "Only Lua function can share");
   LClosure *f = cast(LClosure *, lua_topointer(L, index));
   luaF_shareproto(f->p);
 }