diff --git a/README.md b/README.md
index 3e33430..6fc6b3f 100644
--- a/README.md
+++ b/README.md
@@ -33,7 +33,7 @@ Alternatively, you can also refer to them with their fully-qualified name:
 
 ```php
 \React\Promise\Stream\buffer(…);
-``` 
+```
 
 ### buffer()
 
@@ -190,8 +190,9 @@ a `Promise` which resolves with a `WritableStreamInterface`.
 
 This function returns a writable stream instance (implementing `WritableStreamInterface`)
 right away which acts as a proxy for the future promise resolution.
+Any writes to this instance will be buffered in memory for when the promise resolves.
 Once the given Promise resolves with a `WritableStreamInterface`, any data you
-wrote to the proxy will be piped to the inner stream.
+have written to the proxy will be forwarded transparently to the inner stream.
 
 ```php
 //$promise = someFunctionWhichResolvesWithAStream();
diff --git a/src/UnwrapWritableStream.php b/src/UnwrapWritableStream.php
index d833f4c..3221305 100644
--- a/src/UnwrapWritableStream.php
+++ b/src/UnwrapWritableStream.php
@@ -16,7 +16,7 @@ class UnwrapWritableStream extends EventEmitter implements WritableStreamInterfa
 {
     private $promise;
     private $stream;
-    private $buffer = '';
+    private $buffer = array();
     private $closed = false;
     private $ending = false;
 
@@ -69,10 +69,15 @@ function (WritableStreamInterface $stream) use ($out, &$store, &$buffer, &$endin
                 $stream->on('close', array($out, 'close'));
                 $out->on('close', array($stream, 'close'));
 
-                if ($buffer !== '') {
+                if ($buffer) {
                     // flush buffer to stream and check if its buffer is not exceeded
-                    $drained = $stream->write($buffer) !== false;
-                    $buffer = '';
+                    $drained = true;
+                    foreach ($buffer as $chunk) {
+                        if (!$stream->write($chunk)) {
+                            $drained = false;
+                        }
+                    }
+                    $buffer = array();
 
                     if ($drained) {
                         // signal drain event, because the output stream previous signalled a full buffer
@@ -109,7 +114,7 @@ public function write($data)
         }
 
         // append to buffer and signal the buffer is full
-        $this->buffer .= $data;
+        $this->buffer[] = $data;
         return false;
     }
 
@@ -128,7 +133,7 @@ public function end($data = null)
 
         // append to buffer
         if ($data !== null) {
-            $this->buffer .= $data;
+            $this->buffer[] = $data;
         }
     }
 
@@ -143,7 +148,7 @@ public function close()
             return;
         }
 
-        $this->buffer = '';
+        $this->buffer = array();
         $this->ending = true;
         $this->closed = true;
 
diff --git a/tests/UnwrapWritableTest.php b/tests/UnwrapWritableTest.php
index d70d85f..ec120e7 100644
--- a/tests/UnwrapWritableTest.php
+++ b/tests/UnwrapWritableTest.php
@@ -5,6 +5,7 @@
 use Clue\React\Block;
 use React\EventLoop\Factory;
 use React\Promise;
+use React\Promise\Deferred;
 use React\Promise\Stream;
 use React\Promise\Timer;
 use React\Stream\ThroughStream;
@@ -149,11 +150,30 @@ public function testForwardsDataImmediatelyIfPromiseIsAlreadyResolved()
         $stream->write('hello');
     }
 
-    public function testForwardsDataInOneGoOncePromiseResolves()
+    public function testForwardsOriginalDataOncePromiseResolves()
     {
+        $data = new \stdClass();
+
         $input = $this->getMockBuilder('React\Stream\WritableStreamInterface')->getMock();
         $input->expects($this->once())->method('isWritable')->willReturn(true);
-        $input->expects($this->once())->method('write')->with('helloworld');
+        $input->expects($this->once())->method('write')->with($data);
+        $input->expects($this->never())->method('end');
+
+        $promise = Timer\resolve(0.001, $this->loop)->then(function () use ($input) {
+            return $input;
+        });
+        $stream = Stream\unwrapWritable($promise);
+
+        $stream->write($data);
+
+        $this->loop->run();
+    }
+
+    public function testForwardsDataInOriginalChunksOncePromiseResolves()
+    {
+        $input = $this->getMockBuilder('React\Stream\WritableStreamInterface')->getMock();
+        $input->expects($this->once())->method('isWritable')->willReturn(true);
+        $input->expects($this->exactly(2))->method('write')->withConsecutive(array('hello'), array('world'));
         $input->expects($this->never())->method('end');
 
         $promise = Timer\resolve(0.001, $this->loop)->then(function () use ($input) {
@@ -185,7 +205,7 @@ public function testForwardsDataAndEndOncePromiseResolves()
     {
         $input = $this->getMockBuilder('React\Stream\WritableStreamInterface')->getMock();
         $input->expects($this->once())->method('isWritable')->willReturn(true);
-        $input->expects($this->once())->method('write')->with('helloworld!');
+        $input->expects($this->exactly(3))->method('write')->withConsecutive(array('hello'), array('world'), array('!'));
         $input->expects($this->once())->method('end');
 
         $promise = Timer\resolve(0.001, $this->loop)->then(function () use ($input) {
@@ -247,6 +267,20 @@ public function testEmitsErrorAndClosesWhenInputEmitsError()
         $this->assertFalse($stream->isWritable());
     }
 
+    public function testDoesNotEmitDrainWhenStreamBufferExceededAfterForwardingData()
+    {
+        $input = $this->getMockBuilder('React\Stream\WritableStreamInterface')->getMock();
+        $input->expects($this->once())->method('isWritable')->willReturn(true);
+        $input->expects($this->once())->method('write')->with('hello')->willReturn(false);
+
+        $deferred = new Deferred();
+        $stream = Stream\unwrapWritable($deferred->promise());
+        $stream->write('hello');
+
+        $stream->on('drain', $this->expectCallableNever());
+        $deferred->resolve($input);
+    }
+
     public function testEmitsDrainWhenInputEmitsDrain()
     {
         $input = new ThroughStream();