diff --git a/index.html b/index.html
index 4c46c9c84..9938836eb 100644
--- a/index.html
+++ b/index.html
@@ -25,6 +25,7 @@
         <script src='js/lib/d3-compat.js'></script>
         <script src='js/lib/queue.js'></script>
         <script src='js/lib/bootstrap-tooltip.js'></script>
+        <script src='js/lib/rtree.js'></script>
 
         <script src='js/id/id.js'></script>
         <script src='js/id/util.js'></script>