diff --git a/composer.json b/composer.json
index 09e50e8..6c52704 100644
--- a/composer.json
+++ b/composer.json
@@ -8,12 +8,10 @@
         "evenement/evenement": "^2.0|^1.0"
     },
     "require-dev": {
-        "react/event-loop": "^0.4|^0.3",
-        "react/promise": "^2.0|^1.0"
+        "react/event-loop": "^0.4|^0.3"
     },
     "suggest": {
-        "react/event-loop": "^0.4",
-        "react/promise": "^2.0"
+        "react/event-loop": "^0.4"
     },
     "autoload": {
         "psr-4": {
diff --git a/src/BufferedSink.php b/src/BufferedSink.php
deleted file mode 100644
index a6b35c0..0000000
--- a/src/BufferedSink.php
+++ /dev/null
@@ -1,59 +0,0 @@
-<?php
-
-namespace React\Stream;
-
-use React\Promise\Deferred;
-use React\Promise\PromisorInterface;
-
-class BufferedSink extends WritableStream implements PromisorInterface
-{
-    private $buffer = '';
-    private $deferred;
-
-    public function __construct()
-    {
-        $this->deferred = new Deferred();
-
-        $this->on('pipe', array($this, 'handlePipeEvent'));
-        $this->on('error', array($this, 'handleErrorEvent'));
-    }
-
-    public function handlePipeEvent($source)
-    {
-        Util::forwardEvents($source, $this, array('error'));
-    }
-
-    public function handleErrorEvent($e)
-    {
-        $this->deferred->reject($e);
-    }
-
-    public function write($data)
-    {
-        $this->buffer .= $data;
-        $this->deferred->progress($data);
-    }
-
-    public function close()
-    {
-        if ($this->closed) {
-            return;
-        }
-
-        parent::close();
-        $this->deferred->resolve($this->buffer);
-    }
-
-    public function promise()
-    {
-        return $this->deferred->promise();
-    }
-
-    public static function createPromise(ReadableStreamInterface $stream)
-    {
-        $sink = new static();
-        $stream->pipe($sink);
-
-        return $sink->promise();
-    }
-}
diff --git a/tests/BufferedSinkTest.php b/tests/BufferedSinkTest.php
deleted file mode 100644
index ee374d6..0000000
--- a/tests/BufferedSinkTest.php
+++ /dev/null
@@ -1,194 +0,0 @@
-<?php
-
-namespace React\Tests\Stream;
-
-use React\Stream\BufferedSink;
-use React\Stream\ReadableStream;
-
-/**
- * @covers React\Stream\BufferedSink
- */
-class BufferedSinkTest extends TestCase
-{
-    /** @test */
-    public function promiseShouldReturnPromise()
-    {
-        $sink = new BufferedSink();
-        $contents = $sink->promise();
-
-        $this->assertInstanceOf('React\Promise\PromiseInterface', $contents);
-    }
-
-    /** @test */
-    public function endShouldResolvePromiseWithBufferContents()
-    {
-        $callback = $this->expectCallableOnceWith('foo');
-
-        $sink = new BufferedSink();
-        $sink
-            ->promise()
-            ->then($callback);
-
-        $sink->write('foo');
-        $sink->end();
-    }
-
-    /** @test */
-    public function closeWithEmptyBufferShouldResolveToEmptyString()
-    {
-        $callback = $this->expectCallableOnceWith('');
-
-        $sink = new BufferedSink();
-        $sink
-            ->promise()
-            ->then($callback);
-
-        $sink->close();
-        $sink->close();
-    }
-
-    /** @test */
-    public function closeTwiceShouldBeFine()
-    {
-        $callback = $this->expectCallableOnce();
-
-        $sink = new BufferedSink();
-        $sink
-            ->promise()
-            ->then($callback);
-
-        $sink->close();
-        $sink->close();
-    }
-
-    /** @test */
-    public function resovedValueShouldContainMultipleWrites()
-    {
-        $callback = $this->expectCallableOnceWith('foobarbaz');
-
-        $sink = new BufferedSink();
-        $sink
-            ->promise()
-            ->then($callback);
-
-        $sink->write('foo');
-        $sink->write('bar');
-        $sink->write('baz');
-        $sink->end();
-    }
-
-    /** @test */
-    public function dataWrittenOnEndShouldBeBuffered()
-    {
-        $callback = $this->expectCallableOnceWith('foobar');
-
-        $sink = new BufferedSink();
-        $sink
-            ->promise()
-            ->then($callback);
-
-        $sink->write('foo');
-        $sink->end('bar');
-    }
-
-    /** @test */
-    public function errorsShouldRejectPromise()
-    {
-        $errback = $this->expectCallableOnceWith($this->callback(function ($e) {
-            return $e instanceof \Exception && 'Shit happens' === $e->getMessage();
-        }));
-
-        $sink = new BufferedSink();
-        $sink
-            ->promise()
-            ->then($this->expectCallableNever(), $errback);
-
-        $sink->emit('error', array(new \Exception('Shit happens')));
-    }
-
-    /** @test */
-    public function writeShouldTriggerProgressOnPromise()
-    {
-        $callback = $this->createCallableMock();
-        $callback
-            ->expects($this->at(0))
-            ->method('__invoke')
-            ->with('foo');
-        $callback
-            ->expects($this->at(1))
-            ->method('__invoke')
-            ->with('bar');
-        $callback
-            ->expects($this->at(2))
-            ->method('__invoke')
-            ->with('baz');
-
-        $sink = new BufferedSink();
-        $sink
-            ->promise()
-            ->then(null, null, $callback);
-
-        $sink->write('foo');
-        $sink->write('bar');
-        $sink->end('baz');
-    }
-
-    /** @test */
-    public function forwardedErrorsFromPipeShouldRejectPromise()
-    {
-        $errback = $this->expectCallableOnceWith($this->callback(function ($e) {
-            return $e instanceof \Exception && 'Shit happens' === $e->getMessage();
-        }));
-
-        $sink = new BufferedSink();
-        $sink
-            ->promise()
-            ->then($this->expectCallableNever(), $errback);
-
-        $readable = new ReadableStream();
-        $readable->pipe($sink);
-        $readable->emit('error', array(new \Exception('Shit happens')));
-    }
-
-    /** @test */
-    public function pipeShouldSucceedAndResolve()
-    {
-        $callback = $this->expectCallableOnceWith('foobar');
-
-        $sink = new BufferedSink();
-        $sink
-            ->promise()
-            ->then($callback);
-
-        $readable = new ReadableStream();
-        $readable->pipe($sink);
-        $readable->emit('data', array('foo'));
-        $readable->emit('data', array('bar'));
-        $readable->close();
-    }
-
-    /** @test */
-    public function factoryMethodShouldImplicitlyPipeAndPromise()
-    {
-        $callback = $this->expectCallableOnceWith('foo');
-
-        $readable = new ReadableStream();
-
-        BufferedSink::createPromise($readable)
-            ->then($callback);
-
-        $readable->emit('data', array('foo'));
-        $readable->close();
-    }
-
-    private function expectCallableOnceWith($value)
-    {
-        $callback = $this->createCallableMock();
-        $callback
-            ->expects($this->once())
-            ->method('__invoke')
-            ->with($value);
-
-        return $callback;
-    }
-}