diff --git a/3rd/lua/lstate.c b/3rd/lua/lstate.c
index f7a17ca0..477c0e6d 100644
--- a/3rd/lua/lstate.c
+++ b/3rd/lua/lstate.c
@@ -181,7 +181,7 @@ static void stack_init (lua_State *L1, lua_State *L) {
   int i; CallInfo *ci;
   /* initialize stack array */
   L1->stack = luaM_newvector(L, BASIC_STACK_SIZE + EXTRA_STACK, StackValue);
-  for (i = 0; i < BASIC_STACK_SIZE; i++)
+  for (i = 0; i < BASIC_STACK_SIZE + EXTRA_STACK; i++)
     setnilvalue(s2v(L1->stack + i));  /* erase new stack */
   L1->top = L1->stack;
   L1->stack_last = L1->stack + BASIC_STACK_SIZE;