diff --git a/index.html b/index.html
index 6baee90..06dd08f 100644
--- a/index.html
+++ b/index.html
@@ -20,7 +20,7 @@
     <script type="importmap">
       {
         "imports": {
-          "tslib": "https://unpkg.com/tslib@2.6.2/tslib.es6.min.js",
+          "tslib": "https://unpkg.com/tslib@2.6.2/tslib.js",  <-- CHANGED THIS LINE
           "@material/web/": "https://unpkg.com/@material/web@1.4.1/",
           "lit": "https://unpkg.com/lit@3.1.2/index.js",
           "lit/decorators.js": "https://unpkg.com/lit@3.1.2/decorators.js",