diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index 0bd7b79..a9adfc1 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -3323,12 +3323,12 @@
   } else {
     // TODO(hpayer): This is a short-term hack to make allocation mementos
     // work again in new space.
-    ClearNextMapWord(original_object_size);
+    dominator_allocate->ClearNextMapWord(original_object_size);
   }
 #else
   // TODO(hpayer): This is a short-term hack to make allocation mementos
   // work again in new space.
-  ClearNextMapWord(original_object_size);
+  dominator_allocate->ClearNextMapWord(original_object_size);
 #endif
 
   dominator_allocate->clear_next_map_word_ = clear_next_map_word_;
diff --git a/src/objects.cc b/src/objects.cc
index 3e4601a..15cee1c 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -7829,7 +7829,7 @@
   int current_offset = 0;
   for (descriptor = 0; descriptor < verbatim; descriptor++) {
     if (GetDetails(descriptor).type() == FIELD) current_offset++;
-    result->CopyFrom(descriptor, this, descriptor, witness);
+    result->CopyFrom(descriptor, other, descriptor, witness);
   }
 
   // |verbatim| -> |valid|
diff --git a/src/version.cc b/src/version.cc
index d83f18e..176abf9 100644
--- a/src/version.cc
+++ b/src/version.cc
@@ -35,7 +35,7 @@
 #define MAJOR_VERSION     3
 #define MINOR_VERSION     21
 #define BUILD_NUMBER      5
-#define PATCH_LEVEL       0
+#define PATCH_LEVEL       1
 // Use 1 for candidates and 0 otherwise.
 // (Boolean macro values are not supported by all preprocessors.)
 #define IS_CANDIDATE_VERSION 0
diff --git a/test/mjsunit/regress/regress-merge-descriptors.js b/test/mjsunit/regress/regress-merge-descriptors.js
new file mode 100644
index 0000000..a84a625
--- /dev/null
+++ b/test/mjsunit/regress/regress-merge-descriptors.js
@@ -0,0 +1,92 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+var extend = function (d, b) {
+  function __() { this.constructor = d; }
+  __.prototype = b.prototype;
+  d.prototype = new __();
+};
+
+var Car = (function (Super) {
+  var Car = function () {
+    var self = this;
+
+    Super.call(self);
+
+    Object.defineProperties(self, {
+      "make": {
+        enumerable: true,
+        configurable: true,
+        get: function () {
+          return "Ford";
+        }
+      }
+    });
+
+    self.copy = function () {
+      throw new Error("Meant to be overriden");
+    };
+
+    return self;
+  };
+
+  extend(Car, Super);
+
+  return Car;
+}(Object));
+
+
+var SuperCar = ((function (Super) {
+  var SuperCar = function (make) {
+    var self = this;
+
+    Super.call(self);
+
+
+    Object.defineProperties(self, {
+      "make": {
+        enumerable: true,
+        configurable: true,
+        get: function () {
+          return make;
+        }
+      }
+    });
+
+    // Convert self.copy from CONSTANT to FIELD.
+    self.copy = function () { };
+
+    return self;
+  };
+  extend(SuperCar, Super);
+  return SuperCar;
+})(Car));
+
+assertEquals("Ford", new Car().make);
+assertEquals("Bugatti", new SuperCar("Bugatti").make);
+assertEquals("Lambo", new SuperCar("Lambo").make);
+assertEquals("Shelby", new SuperCar("Shelby").make);