diff --git a/bumper_en.html b/bumper_en.html
index 1f77c76..69d0be1 100644
--- a/bumper_en.html
+++ b/bumper_en.html
@@ -27,7 +27,7 @@
// Preloads, with more included for phet-io brand
let preloads = [
- '../phet-core/js/phet-polyfill.js',
+ '../sherpa/lib/mdn-array-from-polyfill.js',
'../joist/js/splash.js',
'../sherpa/lib/jquery-2.1.0.js',
'../sherpa/lib/lodash-4.17.4.js',