diff --git a/test/js-perf-test/SixSpeed.json b/test/js-perf-test/SixSpeed.json
index 417ec89569..746db951f0 100644
--- a/test/js-perf-test/SixSpeed.json
+++ b/test/js-perf-test/SixSpeed.json
@@ -36,6 +36,20 @@
         {"name": "ObjectLiterals-ES6"}
       ]
     },
+    {
+      "name": "Defaults",
+      "path": ["SixSpeed/defaults"],
+      "main": "run.js",
+      "resources": [
+        "run.js",
+        "defaults.js"
+      ],
+      "results_regexp": "^%s\\(Score\\): (.+)$",
+      "tests": [
+        {"name": "Defaults-ES5"},
+        {"name": "Defaults-ES6"}
+      ]
+    },
     {
       "name": "Spread",
       "path": ["SixSpeed/spread"],
diff --git a/test/js-perf-test/SixSpeed/defaults/defaults.js b/test/js-perf-test/SixSpeed/defaults/defaults.js
new file mode 100644
index 0000000000..b690f8931a
--- /dev/null
+++ b/test/js-perf-test/SixSpeed/defaults/defaults.js
@@ -0,0 +1,47 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This benchmark is based on the six-speed benchmark build output.
+// Copyright 2014 Kevin Decker <https://github.com/kpdecker/six-speed/>
+
+
+new BenchmarkSuite('Defaults-ES5', [1000], [
+  new Benchmark('ES5', false, false, 0, ES5),
+]);
+
+new BenchmarkSuite('Defaults-ES6', [1000], [
+  new Benchmark('ES6', false, false, 0, ES6),
+]);
+
+// ----------------------------------------------------------------------------
+// Benchmark: ES5
+// ----------------------------------------------------------------------------
+
+function ES5() {
+  "use strict";
+  function fn(arg, other) {
+    arg = arg === undefined ? 1 : arg;
+    other = other === undefined ? 3 : other;
+    return other;
+  }
+
+  fn();
+  fn(2);
+  fn(2, 4);
+}
+
+// ----------------------------------------------------------------------------
+// Benchmark: ES6
+// ----------------------------------------------------------------------------
+
+function ES6() {
+  "use strict";
+  function fn(arg = 1, other = 3) {
+    return other;
+  }
+
+  fn();
+  fn(2);
+  fn(2, 4);
+}
diff --git a/test/js-perf-test/SixSpeed/defaults/run.js b/test/js-perf-test/SixSpeed/defaults/run.js
new file mode 100644
index 0000000000..f067164afa
--- /dev/null
+++ b/test/js-perf-test/SixSpeed/defaults/run.js
@@ -0,0 +1,25 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+load('../../base.js');
+load('defaults.js');
+
+var success = true;
+
+function PrintResult(name, result) {
+  print(name + '(Score): ' + result);
+}
+
+
+function PrintError(name, error) {
+  PrintResult(name, error);
+  success = false;
+}
+
+
+BenchmarkSuite.config.doWarmup = undefined;
+BenchmarkSuite.config.doDeterministic = undefined;
+
+BenchmarkSuite.RunSuites({ NotifyResult: PrintResult,
+                           NotifyError: PrintError });