diff --git a/src/smalloc.cc b/src/smalloc.cc
index 1e54ec72f6..7d5c5d4984 100644
--- a/src/smalloc.cc
+++ b/src/smalloc.cc
@@ -173,6 +173,27 @@ void TargetCallback(Isolate* isolate, Persistent<Object>* target, char* data) {
 }
 
 
+Handle<Value> AllocDispose(const Arguments& args) {
+  AllocDispose(args[0]->ToObject());
+  return Undefined(node_isolate);
+}
+
+
+void AllocDispose(Handle<Object> obj) {
+  char* data = static_cast<char*>(obj->GetIndexedPropertiesExternalArrayData());
+  size_t length = obj->GetIndexedPropertiesExternalArrayDataLength();
+
+  if (data == NULL || length == 0)
+    return;
+
+  obj->SetIndexedPropertiesToExternalArrayData(NULL,
+                                               kExternalUnsignedByteArray,
+                                               0);
+  delete[] data;
+  node_isolate->AdjustAmountOfExternalAllocatedMemory(-length);
+}
+
+
 void Alloc(Handle<Object> obj, size_t length, FreeCallback fn, void* hint) {
   assert(length <= kMaxLength);
 
@@ -286,6 +307,8 @@ void Initialize(Handle<Object> exports) {
 
   exports->Set(String::New("alloc"),
                FunctionTemplate::New(Alloc)->GetFunction());
+  exports->Set(String::New("dispose"),
+               FunctionTemplate::New(AllocDispose)->GetFunction());
 
   exports->Set(String::New("kMaxLength"),
                Uint32::New(kMaxLength, node_isolate));
diff --git a/src/smalloc.h b/src/smalloc.h
index 88a9530af6..bfd41cabec 100644
--- a/src/smalloc.h
+++ b/src/smalloc.h
@@ -56,6 +56,12 @@ void Alloc(v8::Handle<v8::Object> obj,
            FreeCallback fn,
            void* hint);
 
+/**
+ * Free memory associated with an externally allocated object. If no external
+ * memory is allocated to the object then nothing will happen.
+ */
+void AllocDispose(v8::Handle<v8::Object> obj);
+
 }  // namespace smalloc
 
 }  // namespace node
diff --git a/test/simple/test-smalloc-dispose-segfault.js b/test/simple/test-smalloc-dispose-segfault.js
new file mode 100644
index 0000000000..22c8587535
--- /dev/null
+++ b/test/simple/test-smalloc-dispose-segfault.js
@@ -0,0 +1,50 @@
+// 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.
+
+var common = require('../common');
+var assert = require('assert');
+
+var spawn = require('child_process').spawn;
+var smalloc = process.binding('smalloc');
+var alloc = smalloc.alloc;
+var dispose = smalloc.dispose;
+
+
+// child
+if (process.argv[2] === 'child') {
+
+  // test that disposing an allocation won't cause the MakeWeakCallback to try
+  // and free invalid memory
+  for (var i = 0; i < 1e4; i++) {
+    dispose(alloc({}, 5));
+    if (i % 10 === 0) gc();
+  }
+
+} else {
+  // test case
+  var child = spawn(process.execPath,
+                ['--expose_gc', __filename, 'child']);
+
+  child.on('exit', function(code, signal) {
+    assert.equal(code, 0, signal);
+    console.log('dispose didn\'t segfault');
+  });
+}
diff --git a/test/simple/test-smalloc.js b/test/simple/test-smalloc.js
index 14450afa44..2a306216a3 100644
--- a/test/simple/test-smalloc.js
+++ b/test/simple/test-smalloc.js
@@ -25,6 +25,7 @@ var assert = require('assert');
 var smalloc = process.binding('smalloc');
 var alloc = smalloc.alloc;
 var copyOnto = smalloc.copyOnto;
+var dispose = smalloc.dispose;
 var sliceOnto = smalloc.sliceOnto;
 
 
@@ -87,3 +88,11 @@ for (var i = 0; i < 6; i++) {
   assert.equal(c[i], i);
   assert.equal(c[i + 6], i * 2);
 }
+
+
+// test disposal
+
+var b = alloc({}, 5);
+dispose(b);
+for (var i = 0; i < 5; i++)
+  assert.equal(b[i], undefined);