diff --git a/lib/ace/ext/language_tools.js b/lib/ace/ext/language_tools.js
index 371fcf29d43..4ba2e34c5bf 100644
--- a/lib/ace/ext/language_tools.js
+++ b/lib/ace/ext/language_tools.js
@@ -50,10 +50,12 @@ var keyWordCompleter = {
 };
 
 var transformSnippetTooltip = function(str) {
-    var record = {}
+    var record = {};
     return str.replace(/\${(\d+)(:(.*?))?}/g, function(_, p1, p2, p3) {
         return (record[p1] = p3 || '');
-    }).replace(/\$(\d+?)/g, (_, p1) => record[p1])
+    }).replace(/\$(\d+?)/g, function (_, p1) {
+        return record[p1];
+    })
 }
 
 var snippetCompleter = {