diff --git a/js/tests/e4x/Regress/regress-354998.js b/js/tests/e4x/Regress/regress-354998.js
new file mode 100755
index 000000000000..f6416b0c496e
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+++ b/js/tests/e4x/Regress/regress-354998.js
@@ -0,0 +1,78 @@
+/* -*- Mode: java; tab-width:8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is JavaScript Engine testing utilities.
+ *
+ * The Initial Developer of the Original Code is
+ * Mozilla Foundation.
+ * Portions created by the Initial Developer are Copyright (C) 2006
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s): Igor Bukanov
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+var bug = 354998;
+var summary = 'prototype should not be enumerated for XML objects.';
+var actual = '';
+var expect = '';
+
+printBugNumber (bug);
+printStatus (summary);
+
+function test()
+{
+  var list = <><a/><b/></>;
+  var count = 0;
+  var now = Date.now;
+  var time = now();
+  for (var i in list) {
+    ++count;
+  }
+  time = now() - time; 
+  if (count != 2) {
+    if (count < 2)
+      throw "Enumerator has not looped over all properties, count="+count;
+    throw "Enumerator has looped over prototype chain of xml, count="+count;
+  }
+  return time;
+}
+
+var time1 = test(); 
+
+for (var i = 0; i != 1000*1000; ++i)
+  Object.prototype[i] = i;
+
+var time2 = test(); 
+if (time1 * 10 < time2) {
+  throw "Assigns to Object.prototype increased time of XML enumeration from "+
+        time1+"ms to "+time2+"ms";
+}
+
+TEST(1, expect, actual);
+
+END();