1 files changed, 2 insertions, 0 deletions
diff --git a/src/lauxlib.js b/src/lauxlib.js
index b4d839d..8cb608d 100644
--- a/src/lauxlib.js
+++ b/src/lauxlib.js
@@ -325,6 +325,8 @@ const luaL_checkstring = luaL_checklstring;
 
 const luaL_optlstring = function(L, arg, def) {
     if (lua.lua_type(L, arg) <= 0) {
+        if (typeof str === "string")
+            def = lua.to_luastring(def);
         return def;
     } else return luaL_checklstring(L, arg);
 };