diff --git a/src/runtime.cc b/src/runtime.cc
index 4758cf1ecc..83eaeecf04 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -6751,6 +6751,27 @@ static Object* Runtime_NewClosure(Arguments args) {
   return *result;
 }
 
+static Object* Runtime_NewObjectFromBound(Arguments args) {
+   HandleScope scope;
+   ASSERT(args.length() == 2);
+   CONVERT_ARG_CHECKED(JSFunction, function, 0);
+   CONVERT_ARG_CHECKED(JSArray, params, 1);
+
+   FixedArray* fixed = FixedArray::cast(params->elements());
+
+   bool exception = false;
+   Object*** param_data = NewArray<Object**>(fixed->length());
+   for (int i = 0; i < fixed->length();  i++) {
+     Handle<Object> val = Handle<Object>(fixed->get(i));
+     param_data[i] = val.location();
+   }
+
+   Handle<Object> result = Execution::New(
+       function, fixed->length(), param_data, &exception);
+   return *result;
+
+}
+
 
 static Code* ComputeConstructStub(Handle<JSFunction> function) {
   Handle<Object> prototype = Factory::null_value();
diff --git a/src/runtime.h b/src/runtime.h
index 1c9bb08057..dca3c7b870 100644
--- a/src/runtime.h
+++ b/src/runtime.h
@@ -258,6 +258,7 @@ namespace internal {
   /* Statements */ \
   F(NewClosure, 2, 1) \
   F(NewObject, 1, 1) \
+  F(NewObjectFromBound, 2, 1) \
   F(Throw, 1, 1) \
   F(ReThrow, 1, 1) \
   F(ThrowReferenceError, 1, 1) \
diff --git a/src/v8natives.js b/src/v8natives.js
index 198cecc3a3..2b7a9bb136 100644
--- a/src/v8natives.js
+++ b/src/v8natives.js
@@ -539,21 +539,21 @@ function DefineOwnProperty(obj, p, desc, should_throw) {
     throw MakeTypeError("define_disallowed", ["defineProperty"]);
 
   if (!IS_UNDEFINED(current) && !current.isConfigurable()) {
-      // Step 5 and 6
-     if ((!desc.hasEnumerable() || 
-          SameValue(desc.isEnumerable() && current.isEnumerable())) &&
-         (!desc.hasConfigurable() || 
-          SameValue(desc.isConfigurable(), current.isConfigurable())) &&
-         (!desc.hasWritable() || 
-          SameValue(desc.isWritable(), current.isWritable())) &&
-         (!desc.hasValue() ||
-          SameValue(desc.getValue(), current.getValue())) &&
-         (!desc.hasGetter() ||
-          SameValue(desc.getGet(), current.getGet())) &&
-         (!desc.hasSetter() ||
-          SameValue(desc.getSet(), current.getSet()))) {
-       return true;
-     }
+    // Step 5 and 6
+    if ((!desc.hasEnumerable() || 
+         SameValue(desc.isEnumerable() && current.isEnumerable())) &&
+        (!desc.hasConfigurable() || 
+         SameValue(desc.isConfigurable(), current.isConfigurable())) &&
+        (!desc.hasWritable() || 
+         SameValue(desc.isWritable(), current.isWritable())) &&
+        (!desc.hasValue() ||
+         SameValue(desc.getValue(), current.getValue())) &&
+        (!desc.hasGetter() ||
+         SameValue(desc.getGet(), current.getGet())) &&
+        (!desc.hasSetter() ||
+         SameValue(desc.getSet(), current.getSet()))) {
+      return true;
+    }
 
     // Step 7
     if (desc.isConfigurable() ||  desc.isEnumerable() != current.isEnumerable())
@@ -1099,6 +1099,57 @@ function FunctionToString() {
 }
 
 
+// ES5 15.3.4.5
+function FunctionBind(this_arg) { // Length is 1.
+  if (!IS_FUNCTION(this)) {
+      throw new $TypeError('Bind must be called on a function');
+  }
+  // this_arg is not an argument that should be bound.
+  var argc_bound = %_ArgumentsLength() - 1;
+  if (argc_bound > 0) {
+    var bound_args = new $Array(argc_bound);
+    for(var i = 0; i < argc_bound; i++) {
+      bound_args[i] = %_Arguments(i+1);
+    }  
+  }
+  global.print(argc_bound);
+  var fn = this;
+  var result = function() {
+    // Combine the args we got from the bind call with the args
+    // given as argument to the invocation. 
+    var argc = %_ArgumentsLength();
+    var args = new $Array(argc + argc_bound);
+    // Add bound arguments.
+    for (var i = 0; i < argc_bound; i++) {
+      args[i] = bound_args[i];
+    }
+    // Add arguments from call.
+    for (var i = 0; i < argc; i++) {
+      args[argc_bound + i] = %_Arguments(i); 
+    }
+    // If this is a construct call we use a special runtime method
+    // to generate the actual object using the bound function.
+    if (%_IsConstructCall()) {
+      return %NewObjectFromBound(fn, args);
+    }
+    return fn.apply(this_arg, args);
+  };
+
+  // We already have caller and arguments properties on functions,
+  // which are non-configurable. It therefore makes no sence to
+  // try to redefine these as defined by the spec. The spec says
+  // that bind should make these throw a TypeError if get or set
+  // is called and make them non-enumerable and non-configurable.
+  // To be consistent with our normal functions we leave this as it is. 
+
+  // Set the correct length.
+  var length = (this.length - argc_bound) > 0 ? this.length - argc_bound : 0;
+  %FunctionSetLength(result, length);
+
+  return result;
+}
+
+
 function NewFunction(arg1) {  // length == 1
   var n = %_ArgumentsLength();
   var p = '';
@@ -1130,6 +1181,7 @@ function NewFunction(arg1) {  // length == 1
 
 function SetupFunction() {
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
+    "bind", FunctionBind,
     "toString", FunctionToString
   ));
 }
diff --git a/test/mjsunit/function-bind.js b/test/mjsunit/function-bind.js
new file mode 100644
index 0000000000..7a72cd5e49
--- /dev/null
+++ b/test/mjsunit/function-bind.js
@@ -0,0 +1,184 @@
+// Copyright 2010 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.
+
+// Tests the Function.prototype.bind (ES 15.3.4.5) method.
+
+// Simple tests.
+function foo(x, y, z) {
+  return x + y + z;
+}
+
+var f = foo.bind(foo);
+assertEquals(3, f(1, 1, 1));
+assertEquals(3, f.length);
+
+f = foo.bind(foo, 2);
+assertEquals(4, f(1, 1));
+assertEquals(2, f.length);
+
+f = foo.bind(foo, 2, 2);
+assertEquals(5, f(1));
+assertEquals(1, f.length);
+
+f = foo.bind(foo, 2, 2, 2);
+assertEquals(6, f());
+assertEquals(0, f.length);
+
+// Test that length works correctly even if more than the actual number
+// of arguments are given when binding.
+f = foo.bind(foo, 1, 2, 3, 4, 5, 6, 7, 8, 9);
+assertEquals(6, f());
+assertEquals(0, f.length);
+
+// Use a different bound object.
+var obj = {x: 42, y: 43};
+// Values that would normally be in "this" when calling f_bound_this.
+var x = 42;
+var y = 44;
+
+function f_bound_this(z) {
+  return z + this.y - this.x;
+} 
+
+assertEquals(3, f_bound_this(1))
+f = f_bound_this.bind(obj);
+assertEquals(2, f(1));
+assertEquals(1, f.length);
+
+f = f_bound_this.bind(obj, 2);
+assertEquals(3, f());
+assertEquals(0, f.length);
+
+// Test chained binds.
+
+// When only giving the thisArg, any number of binds should have 
+// the same effect.
+f = foo.bind(foo);
+assertEquals(3, f(1, 1, 1));
+f = foo.bind(foo).bind(foo).bind(foo).bind(foo);
+assertEquals(3, f(1, 1, 1));
+assertEquals(3, f.length);
+
+// Giving bound parameters should work at any place in the chain.
+f = foo.bind(foo, 1).bind(foo).bind(foo).bind(foo);
+assertEquals(3, f(1, 1));
+assertEquals(2, f.length);
+
+f = foo.bind(foo).bind(foo, 1).bind(foo).bind(foo);
+assertEquals(3, f(1, 1));
+assertEquals(2, f.length);
+
+f = foo.bind(foo).bind(foo).bind(foo,1 ).bind(foo);
+assertEquals(3, f(1, 1));
+assertEquals(2, f.length);
+
+f = foo.bind(foo).bind(foo).bind(foo).bind(foo, 1);
+assertEquals(3, f(1, 1));
+assertEquals(2, f.length);
+
+// Several parameters can be given, and given in different bind invokations.
+f = foo.bind(foo, 1, 1).bind(foo).bind(foo).bind(foo);
+assertEquals(3, f(1));
+assertEquals(1, f.length);
+
+f = foo.bind(foo).bind(foo, 1, 1).bind(foo).bind(foo);
+assertEquals(3, f(1));
+assertEquals(1, f.length);
+
+f = foo.bind(foo).bind(foo, 1, 1).bind(foo).bind(foo);
+assertEquals(3, f(1));
+assertEquals(1, f.length);
+
+f = foo.bind(foo).bind(foo).bind(foo, 1, 1).bind(foo);
+assertEquals(3, f(1));
+assertEquals(1, f.length);
+
+f = foo.bind(foo).bind(foo).bind(foo).bind(foo, 1, 1);
+assertEquals(3, f(1));
+assertEquals(1, f.length);
+
+f = foo.bind(foo, 1).bind(foo, 1).bind(foo).bind(foo);
+assertEquals(3, f(1));
+assertEquals(1, f.length);
+
+f = foo.bind(foo, 1).bind(foo).bind(foo, 1).bind(foo);
+assertEquals(3, f(1));
+assertEquals(1, f.length);
+
+f = foo.bind(foo, 1).bind(foo).bind(foo).bind(foo, 1);
+assertEquals(3, f(1));
+assertEquals(1, f.length);
+
+f = foo.bind(foo).bind(foo, 1).bind(foo).bind(foo, 1);
+assertEquals(3, f(1));
+assertEquals(1, f.length);
+
+// Test constructor calls.
+
+function bar(x, y, z) {
+  this.x = x;
+  this.y = y;
+  this.z = z;
+}
+
+f = bar.bind(bar);
+var obj2 = new f(1,2,3);
+assertEquals(1, obj2.x);
+assertEquals(2, obj2.y);
+assertEquals(3, obj2.z);
+
+f = bar.bind(bar, 1);
+obj2 = new f(2,3);
+assertEquals(1, obj2.x);
+assertEquals(2, obj2.y);
+assertEquals(3, obj2.z);
+
+f = bar.bind(bar, 1, 2);
+obj2 = new f(3);
+assertEquals(1, obj2.x);
+assertEquals(2, obj2.y);
+assertEquals(3, obj2.z);
+
+f = bar.bind(bar, 1, 2, 3);
+obj2 = new f();
+assertEquals(1, obj2.x);
+assertEquals(2, obj2.y);
+assertEquals(3, obj2.z);
+
+
+// Test bind chains when used as a constructor.
+
+f = bar.bind(bar, 1).bind(bar, 2).bind(bar, 3);
+obj2 = new f();
+assertEquals(1, obj2.x);
+assertEquals(2, obj2.y);
+assertEquals(3, obj2.z);
+
+// Test instanceof obj2 is bar, not f.
+assertTrue(obj2 instanceof bar);
+assertFalse(obj2 instanceof f);
+