diff --git a/lib/ace/lib/lang.js b/lib/ace/lib/lang.js
index 863bbb55..921dee1d 100644
--- a/lib/ace/lib/lang.js
+++ b/lib/ace/lib/lang.js
@@ -81,20 +81,24 @@ exports.copyArray = function(array){
     return copy;
 };
 
-exports.deepCopy = function (obj) {
+exports.deepCopy = function deepCopy(obj) {
     if (typeof obj !== "object" || !obj)
         return obj;
+    var copy;
+    if (Array.isArray(obj)) {
+        copy = [];
+        for (var key = 0; key < obj.length; key++) {
+            copy[key] = deepCopy(obj[key]);
+        }
+        return copy;
+    }
     var cons = obj.constructor;
     if (cons === RegExp)
         return obj;
     
-    var copy = cons();
+    copy = cons();
     for (var key in obj) {
-        if (typeof obj[key] === "object") {
-            copy[key] = exports.deepCopy(obj[key]);
-        } else {
-            copy[key] = obj[key];
-        }
+        copy[key] = deepCopy(obj[key]);
     }
     return copy;
 };