diff --git a/app.js b/app.js
index fb29486..2e04ea9 100644
--- a/app.js
+++ b/app.js
@@ -170,7 +170,7 @@ global.syzoj = {
     app.use(Session(sessionConfig));
 
     app.use((req, res, next) => {
-      res.locals.useLocalLibs = !!req.headers['syzoj-no-cdn'];
+      res.locals.useLocalLibs = !!parseInt(req.headers['syzoj-no-cdn']);
 
       let User = syzoj.model('user');
       if (req.session.user_id) {