diff --git a/src/node_contextify.cc b/src/node_contextify.cc
index 9814920b08..4ef6126a46 100644
--- a/src/node_contextify.cc
+++ b/src/node_contextify.cc
@@ -157,6 +157,7 @@ class ContextifyContext {
         if (clone_property_method.IsEmpty()) {
           Local<String> code = FIXED_ONE_BYTE_STRING(node_isolate,
               "(function cloneProperty(source, key, target) {\n"
+              "  if (key === 'Proxy') return;\n"
               "  try {\n"
               "    var desc = Object.getOwnPropertyDescriptor(source, key);\n"
               "    if (desc.value === source) desc.value = target;\n"
diff --git a/test/common.js b/test/common.js
index 97de6d8a01..d44f0ea110 100644
--- a/test/common.js
+++ b/test/common.js
@@ -139,6 +139,15 @@ if (global.ArrayBuffer) {
   knownGlobals.push(DataView);
 }
 
+// Harmony features.
+if (global.Proxy) {
+  knownGlobals.push(Proxy);
+}
+
+if (global.Symbol) {
+  knownGlobals.push(Symbol);
+}
+
 function leakedGlobals() {
   var leaked = [];
 
diff --git a/test/simple/test-vm-harmony-proxies.js b/test/simple/test-vm-harmony-proxies.js
new file mode 100644
index 0000000000..e1b4ec8ad2
--- /dev/null
+++ b/test/simple/test-vm-harmony-proxies.js
@@ -0,0 +1,39 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+// Flags: --harmony_proxies
+
+var common = require('../common');
+var assert = require('assert');
+var vm = require('vm');
+
+// src/node_contextify.cc filters out the Proxy object from the parent
+// context.  Make sure that the new context has a Proxy object of its own.
+var sandbox = {};
+var result = vm.runInNewContext('this.Proxy = Proxy', sandbox);
+assert(typeof sandbox.Proxy === 'object');
+assert(sandbox.Proxy !== Proxy);
+
+// Unless we copy the Proxy object explicitly, of course.
+var sandbox = { Proxy: Proxy };
+var result = vm.runInNewContext('this.Proxy = Proxy', sandbox);
+assert(typeof sandbox.Proxy === 'object');
+assert(sandbox.Proxy === Proxy);
diff --git a/test/simple/test-vm-harmony-symbols.js b/test/simple/test-vm-harmony-symbols.js
new file mode 100644
index 0000000000..4aa4161266
--- /dev/null
+++ b/test/simple/test-vm-harmony-symbols.js
@@ -0,0 +1,38 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+// Flags: --harmony_symbols
+
+var common = require('../common');
+var assert = require('assert');
+var vm = require('vm');
+
+// The sandbox should have its own Symbol constructor.
+var sandbox = {};
+var result = vm.runInNewContext('this.Symbol = Symbol', sandbox);
+assert(typeof sandbox.Symbol === 'function');
+assert(sandbox.Symbol !== Symbol);
+
+// Unless we copy the Symbol constructor explicitly, of course.
+var sandbox = { Symbol: Symbol };
+var result = vm.runInNewContext('this.Symbol = Symbol', sandbox);
+assert(typeof sandbox.Symbol === 'function');
+assert(sandbox.Symbol === Symbol);