diff --git a/index.html b/index.html
index 5f3b59d..98b1d8b 100644
--- a/index.html
+++ b/index.html
@@ -33,9 +33,9 @@
     <script>
         const storymap_options = {};
         const storymap = new KLStoryMap.StoryMap('mapdiv', 'data.json', storymap_options);
-        window.onresize = function(event) {
+        document.addEventListener("resize", function(event) {
             storymap.updateDisplay(); // this isn't automatic
-        }
+        });
     </script>
 </body>
 </html>