diff -r 4ebc2e2fb97c -r 71c04702a3d5 test/nashorn/script/basic/mirror_proto_assign.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/nashorn/script/basic/mirror_proto_assign.js	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,52 @@
+/*
+ * 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-8023368: Instance __proto__ property should exist and be writable.
+ *
+ * @test
+ * @run
+ */
+
+// check that Object.setPrototypeOf works for mirror objects as well.
+
+var global = loadWithNewGlobal({
+    name: "test",
+    script: "var obj = {}; this"
+});
+
+var proto = global.eval("({ foo: 323 })");
+
+Object.setPrototypeOf(global.obj, proto);
+
+function func(obj) {
+    // check proto inherited value
+    print("obj.foo = " + obj.foo);
+}
+
+func(global.obj);
+
+var newProto = global.eval("({ foo: 'hello' })");
+Object.setPrototypeOf(global.obj, newProto);
+
+func(global.obj);