diff --git a/authorization_code/app.js b/authorization_code/app.js
index 9b8a6b55..ca44d917 100644
--- a/authorization_code/app.js
+++ b/authorization_code/app.js
@@ -125,7 +125,7 @@ app.get('/refresh_token', function(req, res) {
   var refresh_token = req.query.refresh_token;
   var authOptions = {
     url: 'https://accounts.spotify.com/api/token',
-    headers: { 'Authorization': 'Basic ' + (new Buffer(client_id + ':' + client_secret).toString('base64')) },
+    headers: { 'Authorization': 'Basic ' + (new Buffer.from(client_id + ':' + client_secret).toString('base64')) },
     form: {
       grant_type: 'refresh_token',
       refresh_token: refresh_token