diff --git a/prototypes/derive-key-ie11.html b/prototypes/derive-key-ie11.html
index 1e072e11..d94bbe23 100644
--- a/prototypes/derive-key-ie11.html
+++ b/prototypes/derive-key-ie11.html
@@ -4,7 +4,8 @@
     <meta charset="utf-8">
 </head>
 <body>
-    <script src="https://dl.dropboxusercontent.com/s/r55397ld512etib/EncoderDecoderTogether.min.js?dl=0" nomodule="" type="text/javascript"></script>
+    <script src="https://unpkg.com/text-encoding@0.6.4/lib/encoding-indexes.js"></script>
+    <script src="https://unpkg.com/text-encoding@0.6.4/lib/encoding.js"></script>
     <script src="https://cdn.jsdelivr.net/npm/promise-polyfill@8/dist/polyfill.min.js"></script>
     <script src="deps/jsSHA/dist/sha512.js"></script>
     <script type="text/javascript" src="https://cdn.rawgit.com/ricmoo/aes-js/e27b99df/index.js"></script>
