diff --git a/src/lauxlib.h b/src/lauxlib.h
index 420b8912..46ac5638 100644
--- a/src/lauxlib.h
+++ b/src/lauxlib.h
@@ -90,7 +90,7 @@ LUALIB_API void (luaL_pushmodule) (lua_State *L, const char *modname,
 				   int sizehint);
 LUALIB_API void *(luaL_testudata) (lua_State *L, int ud, const char *tname);
 LUALIB_API void (luaL_setmetatable) (lua_State *L, const char *tname);
-LUALIB_API int (luaL_len) (lua_State *L, int idx);
+LUALIB_API lua_Integer (luaL_len) (lua_State *L, int idx);
 
 
 /*
diff --git a/src/lj_api.c b/src/lj_api.c
index 641658d2..71888f21 100644
--- a/src/lj_api.c
+++ b/src/lj_api.c
@@ -1221,12 +1221,12 @@ LUALIB_API int luaL_callmeta(lua_State *L, int idx, const char *field)
   return 0;
 }
 
-LUALIB_API int luaL_len(lua_State *L, int idx)
+LUALIB_API lua_Integer luaL_len(lua_State *L, int idx)
 {
-  int l;
+  lua_Integer l;
   int isnum;
   lua_len(L, idx);
-  l = (int)lua_tointegerx(L, -1, &isnum);
+  l = lua_tointegerx(L, -1, &isnum);
   if (!isnum)
     luaL_error(L, "object length is not a number");
   lua_pop(L, 1);  /* remove object */
diff --git a/src/luajit.c b/src/luajit.c
index 4641b0b6..79c629e8 100644
--- a/src/luajit.c
+++ b/src/luajit.c
@@ -274,7 +274,7 @@ static int pushargs(lua_State *L)
   lua_getglobal(L, "arg");
   if (!lua_istable(L, -1))
     luaL_error(L, "'arg' is not a table");
-  n = luaL_len(L, -1);
+  n = (int)luaL_len(L, -1);
   luaL_checkstack(L, n + 3, "too many arguments to script");
   for (i = 1; i <= n; i++)
     lua_rawgeti(L, -i, i);