diff --git a/test/language/statements/for-of/arguments-object-aliasing.js b/test/language/statements/for-of/arguments-mapped-aliasing.js
similarity index 63%
rename from test/language/statements/for-of/arguments-object-aliasing.js
rename to test/language/statements/for-of/arguments-mapped-aliasing.js
index 8528e85224..c3c39154c5 100644
--- a/test/language/statements/for-of/arguments-object-aliasing.js
+++ b/test/language/statements/for-of/arguments-mapped-aliasing.js
@@ -3,9 +3,11 @@
 /*---
 es6id: 13.6.4
 description: >
-    Arguments objects should be able to be traversed using a `for..of` loop,
-    and dynamic changes to their contents should be reflected in the iterated
-    values.
+    Mapped arguments object mutation via alias during traversal using for..of
+info: >
+    "Mapped" arguments objects should be able to be traversed using a `for..of`
+    loop, and dynamic changes to the formal parameters should be reflected in
+    the iterated values.
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/statements/for-of/arguments-object-mutation.js b/test/language/statements/for-of/arguments-mapped-mutation.js
similarity index 60%
rename from test/language/statements/for-of/arguments-object-mutation.js
rename to test/language/statements/for-of/arguments-mapped-mutation.js
index 6d9a0334ca..9191d4d827 100644
--- a/test/language/statements/for-of/arguments-object-mutation.js
+++ b/test/language/statements/for-of/arguments-mapped-mutation.js
@@ -2,10 +2,12 @@
 // This code is governed by the BSD license found in the LICENSE file.
 /*---
 es6id: 13.6.4
-description: >
-    Arguments objects should be able to be traversed using a `for..of` loop,
-    and dynamic changes to their contents should be reflected in the iterated
-    values.
+description: Mapped arguments object mutation during traversal using for..of
+info: >
+    "Mapped" arguments objects should be able to be traversed using a `for..of`
+    loop, and dynamic changes to their contents should be reflected in the
+    iterated values.
+flags: [noStrict]
 ---*/
 
 var expected = [1, 4, 6];
diff --git a/test/language/statements/for-of/arguments-object.js b/test/language/statements/for-of/arguments-mapped.js
similarity index 69%
rename from test/language/statements/for-of/arguments-object.js
rename to test/language/statements/for-of/arguments-mapped.js
index 6c04da407f..58923c573a 100644
--- a/test/language/statements/for-of/arguments-object.js
+++ b/test/language/statements/for-of/arguments-mapped.js
@@ -2,8 +2,11 @@
 // This code is governed by the BSD license found in the LICENSE file.
 /*---
 es6id: 13.6.4
-description: >
-    Arguments objects should be able to be traversed using a `for..of` loop.
+description: Mapped arguments object traversal using for..of
+info: >
+    "Mapped" arguments objects should be able to be traversed using a `for..of`
+    loop.
+flags: [noStrict]
 ---*/
 
 var i = 0;
diff --git a/test/language/statements/for-of/arguments-unmapped-aliasing.js b/test/language/statements/for-of/arguments-unmapped-aliasing.js
new file mode 100644
index 0000000000..fac40f2ac7
--- /dev/null
+++ b/test/language/statements/for-of/arguments-unmapped-aliasing.js
@@ -0,0 +1,29 @@
+// Copyright (C) Copyright 2014 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 13.6.4
+description: >
+    Unmapped arguments object mutation via alias during traversal using for..of
+info: >
+    "Unmapped" arguments objects should be able to be traversed using a
+    `for..of` loop, and dynamic changes to the formal parameters should not be
+    reflected in the iterated values.
+flags: [noStrict]
+---*/
+
+var expected = [1, 2, 3];
+var i = 0;
+
+(function(a, b, c) {
+  'use strict';
+  for (var value of arguments) {
+    a = b;
+    b = c;
+    c = i;
+    assert.sameValue(value, expected[i], 'argument at index ' + i);
+    i++;
+  }
+
+}(1, 2, 3));
+
+assert.sameValue(i, 3, 'Visits all arguments');
diff --git a/test/language/statements/for-of/arguments-unmapped-mutation.js b/test/language/statements/for-of/arguments-unmapped-mutation.js
new file mode 100644
index 0000000000..9c4f441ba7
--- /dev/null
+++ b/test/language/statements/for-of/arguments-unmapped-mutation.js
@@ -0,0 +1,25 @@
+// Copyright (C) Copyright 2014 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 13.6.4
+description: Unmapped arguments object mutation during traversal using for..of
+info: >
+    "Unmapped" arguments objects should be able to be traversed using a
+    `for..of` loop, and dynamic changes to their contents should be reflected
+    in the iterated values.
+flags: [noStrict]
+---*/
+
+var expected = [1, 4, 6];
+var i = 0;
+
+(function() {
+  'use strict';
+  for (var value of arguments) {
+    assert.sameValue(value, expected[i], 'argument at index ' + i);
+    i++;
+    arguments[i] *= 2;
+  }
+}(1, 2, 3));
+
+assert.sameValue(i, 3, 'Visits all arguments');
diff --git a/test/language/statements/for-of/arguments-unmapped.js b/test/language/statements/for-of/arguments-unmapped.js
new file mode 100644
index 0000000000..21020a7af8
--- /dev/null
+++ b/test/language/statements/for-of/arguments-unmapped.js
@@ -0,0 +1,22 @@
+// Copyright (C) Copyright 2014 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 13.6.4
+description: Unmapped arguments object traversal using for..of
+info: >
+    "Umapped" arguments objects should be able to be traversed using a
+    `for..of` loop.
+flags: [noStrict]
+---*/
+
+var i = 0;
+
+(function() {
+  'use strict';
+  for (var value of arguments) {
+    assert.sameValue(value, arguments[i], 'argument at index ' + i);
+    i++;
+  }
+}(0, 'a', true, false, null, undefined, NaN));
+
+assert.sameValue(i, 7, 'Visits all arguments');