diff --git a/src/lj_func.c b/src/lj_func.c
index abb7afd5..231701db 100644
--- a/src/lj_func.c
+++ b/src/lj_func.c
@@ -51,7 +51,7 @@ void LJ_FASTCALL lj_func_freeproto(global_State *g, GCproto *pt)
 		pt->sizekn*(MSize)sizeof(lua_Number);
   lj_mem_free(g, pt->k.gc - nkgc, sizek);
   lj_mem_freevec(g, pt->bc, pt->sizebc, BCIns);
-  lj_mem_freevec(g, pt->uv, pt->sizeuv, int16_t);
+  lj_mem_freevec(g, pt->uv, pt->sizeuv, uint16_t);
   lj_mem_freevec(g, pt->lineinfo, pt->sizelineinfo, int32_t);
   lj_mem_freevec(g, pt->varinfo, pt->sizevarinfo, struct VarInfo);
   lj_mem_freevec(g, pt->uvname, pt->sizeuvname, GCstr *);
@@ -170,7 +170,12 @@ GCfunc *lj_func_newL_gc(lua_State *L, GCproto *pt, GCfuncL *parent)
   base = L->base;
   for (i = 0; i < nuv; i++) {
     ptrdiff_t v = pt->uv[i];
-    GCupval *uv = v < 0 ? &gcref(puv[~v])->uv : func_finduv(L, base + v);
+    GCupval *uv;
+    if ((v & 0x8000)) {
+      uv = func_finduv(L, base + (v & 0xff));
+    } else {
+      uv = &gcref(puv[v])->uv;
+    }
     setgcref(fn->l.uvptr[i], obj2gco(uv));
   }
   return fn;
diff --git a/src/lj_gc.c b/src/lj_gc.c
index ffe5d4b1..cd99f249 100644
--- a/src/lj_gc.c
+++ b/src/lj_gc.c
@@ -329,7 +329,7 @@ static size_t propagatemark(global_State *g)
     return sizeof(GCproto) + sizeof(BCIns) * pt->sizebc +
 			     sizeof(GCRef) * pt->sizekgc +
 			     sizeof(lua_Number) * pt->sizekn +
-			     sizeof(int16_t) * pt->sizeuv +
+			     sizeof(uint16_t) * pt->sizeuv +
 			     sizeof(int32_t) * pt->sizelineinfo +
 			     sizeof(VarInfo) * pt->sizevarinfo +
 			     sizeof(GCstr *) * pt->sizeuvname;
diff --git a/src/lj_obj.h b/src/lj_obj.h
index c237ebf5..85d904f3 100644
--- a/src/lj_obj.h
+++ b/src/lj_obj.h
@@ -358,7 +358,7 @@ typedef struct GCproto {
   GCRef gclist;
   ProtoK k;		/* Split constant array (points to the middle). */
   BCIns *bc;		/* Array of bytecode instructions. */
-  int16_t *uv;		/* Upvalue list. local >= 0. parent uv < 0. */
+  uint16_t *uv;		/* Upvalue list. local slot|0x8000 or parent uv idx. */
   MSize sizekgc;	/* Number of collectable constants. */
   MSize sizekn;		/* Number of lua_Number constants. */
   uint8_t sizeuv;	/* Number of upvalues. */
diff --git a/src/lj_parse.c b/src/lj_parse.c
index 81416f0f..8e94faa4 100644
--- a/src/lj_parse.c
+++ b/src/lj_parse.c
@@ -1014,7 +1014,7 @@ static uint32_t indexupvalue(FuncState *fs, GCstr *name, ExpDesc *v)
   uint32_t i;
   GCproto *pt = fs->pt;
   for (i = 0; i < fs->nuv; i++) {
-    if (fs->upvalues[i].k == v->k && fs->upvalues[i].info == v->u.s.info) {
+    if (fs->upvalues[i].info == v->u.s.info && fs->upvalues[i].k == v->k) {
       lua_assert(pt->uvname[i] == name);
       return i;
     }
@@ -1171,12 +1171,12 @@ static void collectk(FuncState *fs, GCproto *pt)
 static void collectuv(FuncState *fs, GCproto *pt)
 {
   uint32_t i;
-  pt->uv = lj_mem_newvec(fs->L, fs->nuv, int16_t);
+  pt->uv = lj_mem_newvec(fs->L, fs->nuv, uint16_t);
   pt->sizeuv = fs->nuv;
   for (i = 0; i < pt->sizeuv; i++) {
     uint32_t v = fs->upvalues[i].info;
-    if (fs->upvalues[i].k == VUPVAL) v = ~v;
-    pt->uv[i] = (int16_t)v;
+    if (fs->upvalues[i].k == VLOCAL) v |= 0x8000;
+    pt->uv[i] = (uint16_t)v;
   }
 }