diff --git a/3rd/lua/lfunc.c b/3rd/lua/lfunc.c
index 20dfc151..0141f98a 100644
--- a/3rd/lua/lfunc.c
+++ b/3rd/lua/lfunc.c
@@ -155,6 +155,7 @@ void luaF_shareproto (Proto *f) {
   int i;
   if (f == NULL)
     return;
+  makeshared(f);
   MAKESHARED(f->source);
   for (i = 0; i < f->sizek; i++) {
     if (ttnov(&f->k[i]) == LUA_TSTRING)
diff --git a/3rd/lua/lgc.c b/3rd/lua/lgc.c
index dfe12044..a3cd6654 100644
--- a/3rd/lua/lgc.c
+++ b/3rd/lua/lgc.c
@@ -266,8 +266,10 @@ static void reallymarkobject (global_State *g, GCObject *o) {
       break;
     }
     case LUA_TLCL: {
-      white2gray(o);
-      linkgclist(gco2lcl(o), g->gray);
+      if (!isshared(o)) {
+        white2gray(o);
+        linkgclist(gco2lcl(o), g->gray);
+	  }
       break;
     }
     case LUA_TCCL: {
diff --git a/3rd/lua/lstring.c b/3rd/lua/lstring.c
index 20bc9f5d..4bec4a7c 100644
--- a/3rd/lua/lstring.c
+++ b/3rd/lua/lstring.c
@@ -935,6 +935,7 @@ new_string(unsigned int h, const char *str, lu_byte l) {
 	memset(ts, 0, sz);
 	setbits(ts->marked, WHITEBITS);
 	gray2black(ts);
+	makeshared(ts);
 	ts->tt = LUA_TSHRSTR;
 	ts->hash = h;
 	ts->shrlen = l;
diff --git a/lualib-src/lua-sharetable.c b/lualib-src/lua-sharetable.c
index 0dbb5256..18ec781b 100644
--- a/lualib-src/lua-sharetable.c
+++ b/lualib-src/lua-sharetable.c
@@ -39,8 +39,12 @@ mark_shared(lua_State *L) {
 			case LUA_TLIGHTUSERDATA:
 				break;
 			case LUA_TFUNCTION:
-				if (!lua_iscfunction(L, idx) || lua_getupvalue(L, idx, 1) != NULL)
-					luaL_error(L, "Invalid function");
+				if (lua_getupvalue(L, idx, 1) != NULL) {
+					luaL_error(L, "Invalid function with upvalue");
+				} else if (!lua_iscfunction(L, idx)) {
+					LClosure *f = (LClosure *)lua_topointer(L, idx);
+					makeshared(f);
+				}
 				break;
 			case LUA_TSTRING:
 				lua_sharestring(L, idx);