diff --git a/www/js/util.js b/www/js/util.js
index dadeb99..8347236 100644
--- a/www/js/util.js
+++ b/www/js/util.js
@@ -32,8 +32,7 @@ const PACK = {
             str += String.fromCharCode(bytes[i]);
         }
         let enc = window.btoa(str);
-        enc.replace("/", "-");
-        return enc;
+        return enc.replace("/", "-");
     },
 };
 
@@ -131,7 +130,7 @@ const UNPACK = {
         return str;
     },
     base64(data) {
-        data.replace("-", "/");
+        data = data.replace("-", "/");
         let str = window.atob(data);
         let bytes = new Uint8Array(str.length);
         for(let i = 0; i < bytes.length; ++i) {