diff --git a/index.js b/index.js
index 72ddb40..341c346 100644
--- a/index.js
+++ b/index.js
@@ -2,7 +2,7 @@
   "use strict";
 
   function atob(str) {
-    return new Buffer(str, 'base64').toString('utf8');
+    return new Buffer(str).toString('base64');
   }
 
   module.exports = atob;