diff --git a/3rd/lua/lapi.c b/3rd/lua/lapi.c
index e2415d62..7500bc79 100644
--- a/3rd/lua/lapi.c
+++ b/3rd/lua/lapi.c
@@ -1018,13 +1018,8 @@ LUA_API int lua_load (lua_State *L, lua_Reader reader, void *data,
 LUA_API void lua_clonefunction (lua_State *L, const void * fp) {
   LClosure *cl;
   LClosure *f = cast(LClosure *, fp);
+  api_check(L, isshared(gcvalue(f->p)), "Not a shared proto");
   lua_lock(L);
-  if (f->p->l_G == G(L)) {
-    setclLvalue(L,L->top,f);
-    api_incr_top(L);
-    lua_unlock(L);
-    return;
-  }
   cl = luaF_newLclosure(L,f->nupvalues);
   setclLvalue(L,L->top,cl);
   api_incr_top(L);
diff --git a/3rd/lua/lfunc.c b/3rd/lua/lfunc.c
index 0141f98a..2cc9a6ce 100644
--- a/3rd/lua/lfunc.c
+++ b/3rd/lua/lfunc.c
@@ -117,7 +117,6 @@ Proto *luaF_newproto (lua_State *L) {
   f->linedefined = 0;
   f->lastlinedefined = 0;
   f->source = NULL;
-  f->l_G = G(L);
   return f;
 }
 
diff --git a/3rd/lua/lgc.c b/3rd/lua/lgc.c
index a3cd6654..757dbd53 100644
--- a/3rd/lua/lgc.c
+++ b/3rd/lua/lgc.c
@@ -496,8 +496,6 @@ static lu_mem traversetable (global_State *g, Table *h) {
 */
 static int traverseproto (global_State *g, Proto *f) {
   int i;
-  if (g != f->l_G)
-    return 0;
   markobjectN(g, f->source);
   for (i = 0; i < f->sizek; i++)  /* mark literals */
     markvalue(g, &f->k[i]);
diff --git a/3rd/lua/lobject.h b/3rd/lua/lobject.h
index c99e0f63..71f55b26 100644
--- a/3rd/lua/lobject.h
+++ b/3rd/lua/lobject.h
@@ -425,7 +425,6 @@ typedef struct Proto {
   Upvaldesc *upvalues;  /* upvalue information */
   TString  *source;  /* used for debug information */
   GCObject *gclist;
-  void *l_G;  /* global state belongs to */
 } Proto;