diff --git a/history.html b/history.html
index b9cefa3..f5b25e3 100644
--- a/history.html
+++ b/history.html
@@ -175,6 +175,7 @@
     <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto+Slab:700,400">
     <link rel="stylesheet" href="https://code.ionicframework.com/ionicons/1.5.2/css/ionicons.min.css">
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/Leaflet.awesome-markers/2.0.2/leaflet.awesome-markers.css">
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/es6-shim/0.27.1/es6-shim.min.js"></script>
     <script src="https://cdnjs.cloudflare.com/ajax/libs/chroma-js/0.6.3/chroma.min.js"></script>
     <script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.9.0/moment-with-locales.min.js"></script>
     <script src="https://cdnjs.cloudflare.com/ajax/libs/leaflet/0.7.3/leaflet.js"></script>