diff --git a/package.json b/package.json
index 4088949..3711d15 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,8 @@
 {
   "browserslist": [
     "defaults",
-    "ios 8.4"
+    "ios 8.4",
+    "ios 5.1"
   ],
   "scripts": {
     "start": "npm run serve",
diff --git a/src/index.ts b/src/index.ts
index bc765d4..6eb1729 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,3 +1,10 @@
+import 'core-js/stable/url';
+import 'core-js/stable/function';
+
+import Intl from 'intl';
+import 'intl/locale-data/jsonp/en.js';
+window.Intl = Intl;
+
 import { Calendar, CalendarOptions } from '@fullcalendar/core';
 import iCalendarPlugin from '@fullcalendar/icalendar';
 import resourceTimeGridPlugin from '@fullcalendar/resource-timegrid';
@@ -94,12 +101,4 @@ function main() {
   window.setInterval(refresh, 5 * 60 * 1000);
 }
 
-if (!window.Intl) {
-  // No `Intl`, so use and load the polyfill.
-  import('intl').then((intl) => {
-    window.Intl = intl;
-    import('intl/locale-data/jsonp/en.js').then((_) => main());
-  });
-} else {
-  main();
-}
+main();