diff --git a/app.js b/app.js
index 5c28d41..7c844e5 100644
--- a/app.js
+++ b/app.js
@@ -82,7 +82,7 @@ if(redirect_www) {
     if(req.headers.host) {
       if(req.headers.host.slice(0, 4) === 'www.') {
         let newhost = req.headers.host.slice(4)
-        return res.redirect(301, req.protocol + '://' + newhost + req.originalUrl)
+        return res.redirect(301, `${req.protocol}://${newhost}${req.originalUrl}`)
       }
     }
     next()
diff --git a/inc/downloadAndSave.js b/inc/downloadAndSave.js
index ed06adc..911d240 100644
--- a/inc/downloadAndSave.js
+++ b/inc/downloadAndSave.js
@@ -17,7 +17,7 @@ module.exports = function(tools) {
     * https://teddit.net/vids/f3lcdk4ydcl51.mp4
     */
     let valid_video_extensions = ['mp4', 'webm', 'ogg']
-    let invalid_urls = ['self', 'default', 'nsfw', 'image', 'spoiler']
+    let invalid_urls = ['self', 'default', 'nsfw', 'image', 'spoiler', 'undefined', undefined, null, '']
     return new Promise((resolve, reject) => {
       if(!invalid_urls.includes(url)) {
         (async () => {