--- a/src/jdk/nashorn/internal/runtime/resources/mozilla_compat.js	Thu Jul 11 16:34:55 2013 +0530
+++ b/src/jdk/nashorn/internal/runtime/resources/mozilla_compat.js	Thu Jul 11 18:23:13 2013 +0530
@@ -48,7 +48,7 @@
         var _packages = [];
         var global = this;
         var oldNoSuchProperty = global.__noSuchProperty__;
-        global.__noSuchProperty__ = function(name) {
+        var __noSuchProperty__ = function(name) {
             'use strict';
             for (var i in _packages) {
                 try {
@@ -69,6 +69,11 @@
             }
         }
 
+        Object.defineProperty(global, "__noSuchProperty__", {
+            writable: true, configurable: true, enumerable: false,
+            value: __noSuchProperty__
+        });
+
         var prefix = "[JavaPackage ";
         return function() {
             for (var i in arguments) {

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/script/basic/JDK-8020380.js	Thu Jul 11 18:23:13 2013 +0530
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ * 
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ * 
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ * 
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ * 
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * JDK-8020380: __noSuchProperty__ defined in mozilla_compat.js script should be non-enumerable
+ *
+ * @test
+ * @run
+ */
+
+load("nashorn:mozilla_compat.js");
+
+var desc = Object.getOwnPropertyDescriptor(this, "__noSuchProperty__");
+if (typeof desc.enumerable != 'boolean' || desc.enumerable != false) {
+    fail("__noSuchProperty__ is enumerable");
+}