Index: public/javascripts/application.js
===================================================================
--- public/javascripts/application.js	(revision 18444)
+++ public/javascripts/application.js	(working copy)
@@ -1013,11 +1013,11 @@
     // do not attach if Tribute is already initialized
     if (element.dataset.tribute === 'true') {return;}
 
-    const issuesUrl = element.dataset.issuesUrl;
-    const usersUrl = element.dataset.usersUrl;
+    var issuesUrl = element.dataset.issuesUrl;
+    var usersUrl = element.dataset.usersUrl;
 
-    const remoteSearch = function(url, cb) {
-      const xhr = new XMLHttpRequest();
+    var remoteSearch = function(url, cb) {
+      var xhr = new XMLHttpRequest();
       xhr.onreadystatechange = function ()
       {
         if (xhr.readyState === 4) {
@@ -1033,7 +1033,7 @@
       xhr.send();
     };
 
-    const tribute = new Tribute({
+    var tribute = new Tribute({
       trigger: '#',
       values: function (text, cb) {
         remoteSearch(issuesUrl + text, function (issues) {