diff --git a/3rd/lua/ldo.c b/3rd/lua/ldo.c
index a60972b2..cb10dc86 100644
--- a/3rd/lua/ldo.c
+++ b/3rd/lua/ldo.c
@@ -191,7 +191,7 @@ int luaD_reallocstack (lua_State *L, int newsize, int raiseerror) {
       luaM_error(L);
     else return 0;  /* do not raise an error */
   }
-  for (; lim < newsize; lim++)
+  for (; lim < newsize + EXTRA_STACK; lim++)
     setnilvalue(s2v(newstack + lim)); /* erase new segment */
   correctstack(L, L->stack, newstack);
   L->stack = newstack;
diff --git a/3rd/lua/lstate.h b/3rd/lua/lstate.h
index b70564a0..096bafd5 100644
--- a/3rd/lua/lstate.h
+++ b/3rd/lua/lstate.h
@@ -139,7 +139,7 @@ struct lua_longjmp;  /* defined in ldo.c */
 
 #define BASIC_STACK_SIZE        (2*LUA_MINSTACK)
 
-#define stacksize(th)	cast_int((th)->stack_last - (th)->stack)
+#define stacksize(th)  cast_int((th)->stack_last + EXTRA_STACK - (th)->stack)
 
 
 /* kinds of Garbage Collection */