diff --git a/server.js b/server.js
index 189da1c0..4515b529 100644
--- a/server.js
+++ b/server.js
@@ -45,7 +45,10 @@ app.prepare().then(() => {
   server.use(async (ctx, next) => {
     switch (ctx.path) {
       case '/': {
-        const lang = ctx.acceptsLanguages(['zh', 'en']).replace('zh', 'tw');
+        const lang = (ctx.acceptsLanguages(['zh', 'en']) || 'en').replace(
+          'zh',
+          'tw'
+        );
         await send(ctx, `./static/index-${lang}.html`);
         break;
       }