diff --git a/src/Client/Client.php b/src/Client/Client.php
index 7a97349c..c3fd4570 100644
--- a/src/Client/Client.php
+++ b/src/Client/Client.php
@@ -2,9 +2,11 @@
 
 namespace React\Http\Client;
 
+use Psr\Http\Message\RequestInterface;
 use React\EventLoop\LoopInterface;
-use React\Socket\ConnectorInterface;
+use React\Http\Io\ClientRequestStream;
 use React\Socket\Connector;
+use React\Socket\ConnectorInterface;
 
 /**
  * @internal
@@ -22,10 +24,9 @@ public function __construct(LoopInterface $loop, ConnectorInterface $connector =
         $this->connector = $connector;
     }
 
-    public function request($method, $url, array $headers = array(), $protocolVersion = '1.0')
+    /** @return ClientRequestStream */
+    public function request(RequestInterface $request)
     {
-        $requestData = new RequestData($method, $url, $headers, $protocolVersion);
-
-        return new Request($this->connector, $requestData);
+        return new ClientRequestStream($this->connector, $request);
     }
 }
diff --git a/src/Client/RequestData.php b/src/Client/RequestData.php
deleted file mode 100644
index 04bb4cad..00000000
--- a/src/Client/RequestData.php
+++ /dev/null
@@ -1,127 +0,0 @@
-<?php
-
-namespace React\Http\Client;
-
-/**
- * @internal
- */
-class RequestData
-{
-    private $method;
-    private $url;
-    private $headers;
-    private $protocolVersion;
-
-    public function __construct($method, $url, array $headers = array(), $protocolVersion = '1.0')
-    {
-        $this->method = $method;
-        $this->url = $url;
-        $this->headers = $headers;
-        $this->protocolVersion = $protocolVersion;
-    }
-
-    private function mergeDefaultheaders(array $headers)
-    {
-        $port = ($this->getDefaultPort() === $this->getPort()) ? '' : ":{$this->getPort()}";
-        $connectionHeaders = ('1.1' === $this->protocolVersion) ? array('Connection' => 'close') : array();
-        $authHeaders = $this->getAuthHeaders();
-
-        $defaults = array_merge(
-            array(
-                'Host'          => $this->getHost().$port,
-            ),
-            $connectionHeaders,
-            $authHeaders
-        );
-
-        // remove all defaults that already exist in $headers
-        $lower = array_change_key_case($headers, CASE_LOWER);
-        foreach ($defaults as $key => $_) {
-            if (isset($lower[strtolower($key)])) {
-                unset($defaults[$key]);
-            }
-        }
-
-        return array_merge($defaults, $headers);
-    }
-
-    public function getScheme()
-    {
-        return parse_url($this->url, PHP_URL_SCHEME);
-    }
-
-    public function getHost()
-    {
-        return parse_url($this->url, PHP_URL_HOST);
-    }
-
-    public function getPort()
-    {
-        return (int) parse_url($this->url, PHP_URL_PORT) ?: $this->getDefaultPort();
-    }
-
-    public function getDefaultPort()
-    {
-        return ('https' === $this->getScheme()) ? 443 : 80;
-    }
-
-    public function getPath()
-    {
-        $path = parse_url($this->url, PHP_URL_PATH);
-        $queryString = parse_url($this->url, PHP_URL_QUERY);
-
-        // assume "/" path by default, but allow "OPTIONS *"
-        if ($path === null) {
-            $path = ($this->method === 'OPTIONS' && $queryString === null) ? '*': '/';
-        }
-        if ($queryString !== null) {
-            $path .= '?' . $queryString;
-        }
-
-        return $path;
-    }
-
-    public function setProtocolVersion($version)
-    {
-        $this->protocolVersion = $version;
-    }
-
-    public function __toString()
-    {
-        $headers = $this->mergeDefaultheaders($this->headers);
-
-        $data = '';
-        $data .= "{$this->method} {$this->getPath()} HTTP/{$this->protocolVersion}\r\n";
-        foreach ($headers as $name => $values) {
-            foreach ((array)$values as $value) {
-                $data .= "$name: $value\r\n";
-            }
-        }
-        $data .= "\r\n";
-
-        return $data;
-    }
-
-    private function getUrlUserPass()
-    {
-        $components = parse_url($this->url);
-
-        if (isset($components['user'])) {
-            return array(
-                'user' => $components['user'],
-                'pass' => isset($components['pass']) ? $components['pass'] : null,
-            );
-        }
-    }
-
-    private function getAuthHeaders()
-    {
-        if (null !== $auth = $this->getUrlUserPass()) {
-            return array(
-                'Authorization' => 'Basic ' . base64_encode($auth['user'].':'.$auth['pass']),
-            );
-        }
-
-        return array();
-    }
-}
diff --git a/src/Client/Request.php b/src/Io/ClientRequestStream.php
similarity index 80%
rename from src/Client/Request.php
rename to src/Io/ClientRequestStream.php
index 51e03313..29536e88 100644
--- a/src/Client/Request.php
+++ b/src/Io/ClientRequestStream.php
@@ -1,8 +1,9 @@
 <?php
 
-namespace React\Http\Client;
+namespace React\Http\Io;
 
 use Evenement\EventEmitter;
+use Psr\Http\Message\RequestInterface;
 use React\Promise;
 use React\Socket\ConnectionInterface;
 use React\Socket\ConnectorInterface;
@@ -16,17 +17,22 @@
  * @event end
  * @internal
  */
-class Request extends EventEmitter implements WritableStreamInterface
+class ClientRequestStream extends EventEmitter implements WritableStreamInterface
 {
     const STATE_INIT = 0;
     const STATE_WRITING_HEAD = 1;
     const STATE_HEAD_WRITTEN = 2;
     const STATE_END = 3;
 
+    /** @var ConnectorInterface */
     private $connector;
-    private $requestData;
 
+    /** @var RequestInterface */
+    private $request;
+
+    /** @var ?ConnectionInterface */
     private $stream;
+
     private $buffer;
     private $responseFactory;
     private $state = self::STATE_INIT;
@@ -34,10 +40,10 @@ class Request extends EventEmitter implements WritableStreamInterface
 
     private $pendingWrites = '';
 
-    public function __construct(ConnectorInterface $connector, RequestData $requestData)
+    public function __construct(ConnectorInterface $connector, RequestInterface $request)
     {
         $this->connector = $connector;
-        $this->requestData = $requestData;
+        $this->request = $request;
     }
 
     public function isWritable()
@@ -49,7 +55,7 @@ private function writeHead()
     {
         $this->state = self::STATE_WRITING_HEAD;
 
-        $requestData = $this->requestData;
+        $request = $this->request;
         $streamRef = &$this->stream;
         $stateRef = &$this->state;
         $pendingWrites = &$this->pendingWrites;
@@ -57,8 +63,9 @@ private function writeHead()
 
         $promise = $this->connect();
         $promise->then(
-            function (ConnectionInterface $stream) use ($requestData, &$streamRef, &$stateRef, &$pendingWrites, $that) {
+            function (ConnectionInterface $stream) use ($request, &$streamRef, &$stateRef, &$pendingWrites, $that) {
                 $streamRef = $stream;
+                assert($streamRef instanceof ConnectionInterface);
 
                 $stream->on('drain', array($that, 'handleDrain'));
                 $stream->on('data', array($that, 'handleData'));
@@ -66,11 +73,18 @@ function (ConnectionInterface $stream) use ($requestData, &$streamRef, &$stateRe
                 $stream->on('error', array($that, 'handleError'));
                 $stream->on('close', array($that, 'handleClose'));
 
-                $headers = (string) $requestData;
+                assert($request instanceof RequestInterface);
+                $headers = "{$request->getMethod()} {$request->getRequestTarget()} HTTP/{$request->getProtocolVersion()}\r\n";
+                foreach ($request->getHeaders() as $name => $values) {
+                    foreach ($values as $value) {
+                        $headers .= "$name: $value\r\n";
+                    }
+                }
 
-                $more = $stream->write($headers . $pendingWrites);
+                $more = $stream->write($headers . "\r\n" . $pendingWrites);
 
-                $stateRef = Request::STATE_HEAD_WRITTEN;
+                assert($stateRef === ClientRequestStream::STATE_WRITING_HEAD);
+                $stateRef = ClientRequestStream::STATE_HEAD_WRITTEN;
 
                 // clear pending writes if non-empty
                 if ($pendingWrites !== '') {
@@ -217,20 +231,24 @@ public function close()
 
     protected function connect()
     {
-        $scheme = $this->requestData->getScheme();
+        $scheme = $this->request->getUri()->getScheme();
         if ($scheme !== 'https' && $scheme !== 'http') {
             return Promise\reject(
                 new \InvalidArgumentException('Invalid request URL given')
             );
         }
 
-        $host = $this->requestData->getHost();
-        $port = $this->requestData->getPort();
+        $host = $this->request->getUri()->getHost();
+        $port = $this->request->getUri()->getPort();
 
         if ($scheme === 'https') {
             $host = 'tls://' . $host;
         }
 
+        if ($port === null) {
+            $port = $scheme === 'https' ? 443 : 80;
+        }
+
         return $this->connector
             ->connect($host . ':' . $port);
     }
diff --git a/src/Io/Sender.php b/src/Io/Sender.php
index 2f04c797..2e821f5a 100644
--- a/src/Io/Sender.php
+++ b/src/Io/Sender.php
@@ -74,6 +74,9 @@ public function __construct(HttpClient $http)
      */
     public function send(RequestInterface $request)
     {
+        // support HTTP/1.1 and HTTP/1.0 only, ensured by `Browser` already
+        assert(\in_array($request->getProtocolVersion(), array('1.0', '1.1'), true));
+
         $body = $request->getBody();
         $size = $body->getSize();
 
@@ -91,12 +94,17 @@ public function send(RequestInterface $request)
             $size = 0;
         }
 
-        $headers = array();
-        foreach ($request->getHeaders() as $name => $values) {
-            $headers[$name] = implode(', ', $values);
+        // automatically add `Connection: close` request header for HTTP/1.1 requests to avoid connection reuse
+        if ($request->getProtocolVersion() === '1.1' && !$request->hasHeader('Connection')) {
+            $request = $request->withHeader('Connection', 'close');
+        }
+
+        // automatically add `Authorization: Basic …` request header if URL includes `user:pass@host`
+        if ($request->getUri()->getUserInfo() !== '' && !$request->hasHeader('Authorization')) {
+            $request = $request->withHeader('Authorization', 'Basic ' . \base64_encode($request->getUri()->getUserInfo()));
         }
 
-        $requestStream = $this->http->request($request->getMethod(), (string)$request->getUri(), $headers, $request->getProtocolVersion());
+        $requestStream = $this->http->request($request);
 
         $deferred = new Deferred(function ($_, $reject) use ($requestStream) {
             // close request stream if request is cancelled
diff --git a/tests/Client/FunctionalIntegrationTest.php b/tests/Client/FunctionalIntegrationTest.php
index d95bf828..90d8444b 100644
--- a/tests/Client/FunctionalIntegrationTest.php
+++ b/tests/Client/FunctionalIntegrationTest.php
@@ -5,6 +5,7 @@
 use Psr\Http\Message\ResponseInterface;
 use React\EventLoop\Loop;
 use React\Http\Client\Client;
+use React\Http\Message\Request;
 use React\Promise\Deferred;
 use React\Promise\Stream;
 use React\Socket\ConnectionInterface;
@@ -45,7 +46,7 @@ public function testRequestToLocalhostEmitsSingleRemoteConnection()
         $port = parse_url($socket->getAddress(), PHP_URL_PORT);
 
         $client = new Client(Loop::get());
-        $request = $client->request('GET', 'http://localhost:' . $port);
+        $request = $client->request(new Request('GET', 'http://localhost:' . $port, array(), '', '1.0'));
 
         $promise = Stream\first($request, 'close');
         $request->end();
@@ -62,7 +63,7 @@ public function testRequestLegacyHttpServerWithOnlyLineFeedReturnsSuccessfulResp
         });
 
         $client = new Client(Loop::get());
-        $request = $client->request('GET', str_replace('tcp:', 'http:', $socket->getAddress()));
+        $request = $client->request(new Request('GET', str_replace('tcp:', 'http:', $socket->getAddress()), array(), '', '1.0'));
 
         $once = $this->expectCallableOnceWith('body');
         $request->on('response', function (ResponseInterface $response, ReadableStreamInterface $body) use ($once) {
@@ -83,7 +84,7 @@ public function testSuccessfulResponseEmitsEnd()
 
         $client = new Client(Loop::get());
 
-        $request = $client->request('GET', 'http://www.google.com/');
+        $request = $client->request(new Request('GET', 'http://www.google.com/', array(), '', '1.0'));
 
         $once = $this->expectCallableOnce();
         $request->on('response', function (ResponseInterface $response, ReadableStreamInterface $body) use ($once) {
@@ -109,7 +110,7 @@ public function testPostDataReturnsData()
         $client = new Client(Loop::get());
 
         $data = str_repeat('.', 33000);
-        $request = $client->request('POST', 'https://' . (mt_rand(0, 1) === 0 ? 'eu.' : '') . 'httpbin.org/post', array('Content-Length' => strlen($data)));
+        $request = $client->request(new Request('POST', 'https://' . (mt_rand(0, 1) === 0 ? 'eu.' : '') . 'httpbin.org/post', array('Content-Length' => strlen($data)), '', '1.0'));
 
         $deferred = new Deferred();
         $request->on('response', function (ResponseInterface $response, ReadableStreamInterface $body) use ($deferred) {
@@ -141,7 +142,7 @@ public function testPostJsonReturnsData()
         $client = new Client(Loop::get());
 
         $data = json_encode(array('numbers' => range(1, 50)));
-        $request = $client->request('POST', 'https://httpbin.org/post', array('Content-Length' => strlen($data), 'Content-Type' => 'application/json'));
+        $request = $client->request(new Request('POST', 'https://httpbin.org/post', array('Content-Length' => strlen($data), 'Content-Type' => 'application/json'), '', '1.0'));
 
         $deferred = new Deferred();
         $request->on('response', function (ResponseInterface $response, ReadableStreamInterface $body) use ($deferred) {
@@ -170,7 +171,7 @@ public function testCancelPendingConnectionEmitsClose()
 
         $client = new Client(Loop::get());
 
-        $request = $client->request('GET', 'http://www.google.com/');
+        $request = $client->request(new Request('GET', 'http://www.google.com/', array(), '', '1.0'));
         $request->on('error', $this->expectCallableNever());
         $request->on('close', $this->expectCallableOnce());
         $request->end();
diff --git a/tests/Client/RequestDataTest.php b/tests/Client/RequestDataTest.php
deleted file mode 100644
index f6713e85..00000000
--- a/tests/Client/RequestDataTest.php
+++ /dev/null
@@ -1,146 +0,0 @@
-<?php
-
-namespace React\Tests\Http\Client;
-
-use React\Http\Client\RequestData;
-use React\Tests\Http\TestCase;
-
-class RequestDataTest extends TestCase
-{
-    /** @test */
-    public function toStringReturnsHTTPRequestMessage()
-    {
-        $requestData = new RequestData('GET', 'http://www.example.com');
-
-        $expected = "GET / HTTP/1.0\r\n" .
-            "Host: www.example.com\r\n" .
-            "\r\n";
-
-        $this->assertSame($expected, $requestData->__toString());
-    }
-
-    /** @test */
-    public function toStringReturnsHTTPRequestMessageWithEmptyQueryString()
-    {
-        $requestData = new RequestData('GET', 'http://www.example.com/path?hello=world');
-
-        $expected = "GET /path?hello=world HTTP/1.0\r\n" .
-            "Host: www.example.com\r\n" .
-            "\r\n";
-
-        $this->assertSame($expected, $requestData->__toString());
-    }
-
-    /** @test */
-    public function toStringReturnsHTTPRequestMessageWithZeroQueryStringAndRootPath()
-    {
-        $requestData = new RequestData('GET', 'http://www.example.com?0');
-
-        $expected = "GET /?0 HTTP/1.0\r\n" .
-            "Host: www.example.com\r\n" .
-            "\r\n";
-
-        $this->assertSame($expected, $requestData->__toString());
-    }
-
-    /** @test */
-    public function toStringReturnsHTTPRequestMessageWithOptionsAbsoluteRequestForm()
-    {
-        $requestData = new RequestData('OPTIONS', 'http://www.example.com/');
-
-        $expected = "OPTIONS / HTTP/1.0\r\n" .
-            "Host: www.example.com\r\n" .
-            "\r\n";
-
-        $this->assertSame($expected, $requestData->__toString());
-    }
-
-    /** @test */
-    public function toStringReturnsHTTPRequestMessageWithOptionsAsteriskRequestForm()
-    {
-        $requestData = new RequestData('OPTIONS', 'http://www.example.com');
-
-        $expected = "OPTIONS * HTTP/1.0\r\n" .
-            "Host: www.example.com\r\n" .
-            "\r\n";
-
-        $this->assertSame($expected, $requestData->__toString());
-    }
-
-    /** @test */
-    public function toStringReturnsHTTPRequestMessageWithProtocolVersion()
-    {
-        $requestData = new RequestData('GET', 'http://www.example.com');
-        $requestData->setProtocolVersion('1.1');
-
-        $expected = "GET / HTTP/1.1\r\n" .
-            "Host: www.example.com\r\n" .
-            "Connection: close\r\n" .
-            "\r\n";
-
-        $this->assertSame($expected, $requestData->__toString());
-    }
-
-    /** @test */
-    public function toStringReturnsHTTPRequestMessageWithHeaders()
-    {
-        $requestData = new RequestData('GET', 'http://www.example.com', array(
-            'User-Agent' => array(),
-            'Via' => array(
-                'first',
-                'second'
-            )
-        ));
-
-        $expected = "GET / HTTP/1.0\r\n" .
-            "Host: www.example.com\r\n" .
-            "Via: first\r\n" .
-            "Via: second\r\n" .
-            "\r\n";
-
-        $this->assertSame($expected, $requestData->__toString());
-    }
-
-    /** @test */
-    public function toStringReturnsHTTPRequestMessageWithHeadersInCustomCase()
-    {
-        $requestData = new RequestData('GET', 'http://www.example.com', array(
-            'user-agent' => 'Hello',
-            'LAST' => 'World'
-        ));
-
-        $expected = "GET / HTTP/1.0\r\n" .
-            "Host: www.example.com\r\n" .
-            "user-agent: Hello\r\n" .
-            "LAST: World\r\n" .
-            "\r\n";
-
-        $this->assertSame($expected, $requestData->__toString());
-    }
-
-    /** @test */
-    public function toStringReturnsHTTPRequestMessageWithProtocolVersionThroughConstructor()
-    {
-        $requestData = new RequestData('GET', 'http://www.example.com', array(), '1.1');
-
-        $expected = "GET / HTTP/1.1\r\n" .
-            "Host: www.example.com\r\n" .
-            "Connection: close\r\n" .
-            "\r\n";
-
-        $this->assertSame($expected, $requestData->__toString());
-    }
-
-    /** @test */
-    public function toStringUsesUserPassFromURL()
-    {
-        $requestData = new RequestData('GET', 'http://john:dummy@www.example.com');
-
-        $expected = "GET / HTTP/1.0\r\n" .
-            "Host: www.example.com\r\n" .
-            "Authorization: Basic am9objpkdW1teQ==\r\n" .
-            "\r\n";
-
-        $this->assertSame($expected, $requestData->__toString());
-    }
-}
diff --git a/tests/Client/RequestTest.php b/tests/Io/ClientRequestStreamTest.php
similarity index 72%
rename from tests/Client/RequestTest.php
rename to tests/Io/ClientRequestStreamTest.php
index cdb209cf..07a4eb73 100644
--- a/tests/Client/RequestTest.php
+++ b/tests/Io/ClientRequestStreamTest.php
@@ -1,16 +1,15 @@
 <?php
 
-namespace React\Tests\Http\Client;
+namespace React\Tests\Http\Io;
 
-use React\Http\Client\Request;
-use React\Http\Client\RequestData;
-use React\Stream\DuplexResourceStream;
-use React\Promise\RejectedPromise;
+use React\Http\Io\ClientRequestStream;
+use React\Http\Message\Request;
 use React\Promise\Deferred;
 use React\Promise\Promise;
+use React\Stream\DuplexResourceStream;
 use React\Tests\Http\TestCase;
 
-class RequestTest extends TestCase
+class ClientRequestStreamTest extends TestCase
 {
     private $connector;
     private $stream;
@@ -31,8 +30,8 @@ public function setUpStream()
     /** @test */
     public function requestShouldBindToStreamEventsAndUseconnector()
     {
-        $requestData = new RequestData('GET', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('GET', 'http://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->successfulConnectionMock();
 
@@ -66,8 +65,8 @@ public function requestShouldBindToStreamEventsAndUseconnector()
      */
     public function requestShouldConnectViaTlsIfUrlUsesHttpsScheme()
     {
-        $requestData = new RequestData('GET', 'https://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('GET', 'https://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->connector->expects($this->once())->method('connect')->with('tls://www.example.com:443')->willReturn(new Promise(function () { }));
 
@@ -77,8 +76,8 @@ public function requestShouldConnectViaTlsIfUrlUsesHttpsScheme()
     /** @test */
     public function requestShouldEmitErrorIfConnectionFails()
     {
-        $requestData = new RequestData('GET', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('GET', 'http://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->connector->expects($this->once())->method('connect')->willReturn(\React\Promise\reject(new \RuntimeException()));
 
@@ -93,8 +92,8 @@ public function requestShouldEmitErrorIfConnectionFails()
     /** @test */
     public function requestShouldEmitErrorIfConnectionClosesBeforeResponseIsParsed()
     {
-        $requestData = new RequestData('GET', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('GET', 'http://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->successfulConnectionMock();
 
@@ -110,8 +109,8 @@ public function requestShouldEmitErrorIfConnectionClosesBeforeResponseIsParsed()
     /** @test */
     public function requestShouldEmitErrorIfConnectionEmitsError()
     {
-        $requestData = new RequestData('GET', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('GET', 'http://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->successfulConnectionMock();
 
@@ -127,8 +126,8 @@ public function requestShouldEmitErrorIfConnectionEmitsError()
     /** @test */
     public function requestShouldEmitErrorIfRequestParserThrowsException()
     {
-        $requestData = new RequestData('GET', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('GET', 'http://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->successfulConnectionMock();
 
@@ -143,8 +142,8 @@ public function requestShouldEmitErrorIfRequestParserThrowsException()
      */
     public function requestShouldEmitErrorIfUrlIsInvalid()
     {
-        $requestData = new RequestData('GET', 'ftp://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('GET', 'ftp://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $request->on('error', $this->expectCallableOnceWith($this->isInstanceOf('InvalidArgumentException')));
 
@@ -159,8 +158,8 @@ public function requestShouldEmitErrorIfUrlIsInvalid()
      */
     public function requestShouldEmitErrorIfUrlHasNoScheme()
     {
-        $requestData = new RequestData('GET', 'www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('GET', 'www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $request->on('error', $this->expectCallableOnceWith($this->isInstanceOf('InvalidArgumentException')));
 
@@ -170,11 +169,51 @@ public function requestShouldEmitErrorIfUrlHasNoScheme()
         $request->end();
     }
 
+    /** @test */
+    public function getRequestShouldSendAGetRequest()
+    {
+        $requestData = new Request('GET', 'http://www.example.com', array(), '', '1.0');
+        $request = new ClientRequestStream($this->connector, $requestData);
+
+        $this->successfulConnectionMock();
+
+        $this->stream->expects($this->once())->method('write')->with("GET / HTTP/1.0\r\nHost: www.example.com\r\n\r\n");
+
+        $request->end();
+    }
+
+    /** @test */
+    public function getHttp11RequestShouldSendAGetRequestWithGivenConnectionCloseHeader()
+    {
+        $requestData = new Request('GET', 'http://www.example.com', array('Connection' => 'close'), '', '1.1');
+        $request = new ClientRequestStream($this->connector, $requestData);
+
+        $this->successfulConnectionMock();
+
+        $this->stream->expects($this->once())->method('write')->with("GET / HTTP/1.1\r\nHost: www.example.com\r\nConnection: close\r\n\r\n");
+
+        $request->end();
+    }
+
+    /** @test */
+    public function getOptionsAsteriskShouldSendAOptionsRequestAsteriskRequestTarget()
+    {
+        $requestData = new Request('OPTIONS', 'http://www.example.com', array('Connection' => 'close'), '', '1.1');
+        $requestData = $requestData->withRequestTarget('*');
+        $request = new ClientRequestStream($this->connector, $requestData);
+
+        $this->successfulConnectionMock();
+
+        $this->stream->expects($this->once())->method('write')->with("OPTIONS * HTTP/1.1\r\nHost: www.example.com\r\nConnection: close\r\n\r\n");
+
+        $request->end();
+    }
+
     /** @test */
     public function postRequestShouldSendAPostRequest()
     {
-        $requestData = new RequestData('POST', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('POST', 'http://www.example.com', array(), '', '1.0');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->successfulConnectionMock();
 
@@ -193,8 +232,8 @@ public function postRequestShouldSendAPostRequest()
     /** @test */
     public function writeWithAPostRequestShouldSendToTheStream()
     {
-        $requestData = new RequestData('POST', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('POST', 'http://www.example.com', array(), '', '1.0');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->successfulConnectionMock();
 
@@ -216,8 +255,8 @@ public function writeWithAPostRequestShouldSendToTheStream()
     /** @test */
     public function writeWithAPostRequestShouldSendBodyAfterHeadersAndEmitDrainEvent()
     {
-        $requestData = new RequestData('POST', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('POST', 'http://www.example.com', array(), '', '1.0');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $resolveConnection = $this->successfulAsyncConnectionMock();
 
@@ -247,8 +286,8 @@ public function writeWithAPostRequestShouldSendBodyAfterHeadersAndEmitDrainEvent
     /** @test */
     public function writeWithAPostRequestShouldForwardDrainEventIfFirstChunkExceedsBuffer()
     {
-        $requestData = new RequestData('POST', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('POST', 'http://www.example.com', array(), '', '1.0');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->stream = $this->getMockBuilder('React\Socket\Connection')
             ->disableOriginalConstructor()
@@ -284,8 +323,8 @@ public function writeWithAPostRequestShouldForwardDrainEventIfFirstChunkExceedsB
     /** @test */
     public function pipeShouldPipeDataIntoTheRequestBody()
     {
-        $requestData = new RequestData('POST', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('POST', 'http://www.example.com', array(), '', '1.0');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->successfulConnectionMock();
 
@@ -317,8 +356,8 @@ public function pipeShouldPipeDataIntoTheRequestBody()
      */
     public function writeShouldStartConnecting()
     {
-        $requestData = new RequestData('POST', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('POST', 'http://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->connector->expects($this->once())
                         ->method('connect')
@@ -333,8 +372,8 @@ public function writeShouldStartConnecting()
      */
     public function endShouldStartConnectingAndChangeStreamIntoNonWritableMode()
     {
-        $requestData = new RequestData('POST', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('POST', 'http://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->connector->expects($this->once())
                         ->method('connect')
@@ -351,8 +390,8 @@ public function endShouldStartConnectingAndChangeStreamIntoNonWritableMode()
      */
     public function closeShouldEmitCloseEvent()
     {
-        $requestData = new RequestData('POST', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('POST', 'http://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $request->on('close', $this->expectCallableOnce());
         $request->close();
@@ -363,8 +402,8 @@ public function closeShouldEmitCloseEvent()
      */
     public function writeAfterCloseReturnsFalse()
     {
-        $requestData = new RequestData('POST', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('POST', 'http://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $request->close();
 
@@ -377,8 +416,8 @@ public function writeAfterCloseReturnsFalse()
      */
     public function endAfterCloseIsNoOp()
     {
-        $requestData = new RequestData('POST', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('POST', 'http://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->connector->expects($this->never())
                         ->method('connect');
@@ -392,8 +431,8 @@ public function endAfterCloseIsNoOp()
      */
     public function closeShouldCancelPendingConnectionAttempt()
     {
-        $requestData = new RequestData('POST', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('POST', 'http://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $promise = new Promise(function () {}, function () {
             throw new \RuntimeException();
@@ -416,8 +455,8 @@ public function closeShouldCancelPendingConnectionAttempt()
     /** @test */
     public function requestShouldRemoveAllListenerAfterClosed()
     {
-        $requestData = new RequestData('GET', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('GET', 'http://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $request->on('close', function () {});
         $this->assertCount(1, $request->listeners('close'));
@@ -450,8 +489,8 @@ private function successfulAsyncConnectionMock()
     /** @test */
     public function multivalueHeader()
     {
-        $requestData = new RequestData('GET', 'http://www.example.com');
-        $request = new Request($this->connector, $requestData);
+        $requestData = new Request('GET', 'http://www.example.com');
+        $request = new ClientRequestStream($this->connector, $requestData);
 
         $this->successfulConnectionMock();
 
diff --git a/tests/Io/SenderTest.php b/tests/Io/SenderTest.php
index 91b87b30..c2357a1a 100644
--- a/tests/Io/SenderTest.php
+++ b/tests/Io/SenderTest.php
@@ -2,8 +2,8 @@
 
 namespace React\Tests\Http\Io;
 
+use Psr\Http\Message\RequestInterface;
 use React\Http\Client\Client as HttpClient;
-use React\Http\Client\RequestData;
 use React\Http\Io\ReadableBodyStream;
 use React\Http\Io\Sender;
 use React\Http\Message\Request;
@@ -71,12 +71,9 @@ public function testSenderConnectorRejection()
     public function testSendPostWillAutomaticallySendContentLengthHeader()
     {
         $client = $this->getMockBuilder('React\Http\Client\Client')->disableOriginalConstructor()->getMock();
-        $client->expects($this->once())->method('request')->with(
-            'POST',
-            'http://www.google.com/',
-            array('Host' => 'www.google.com', 'Content-Length' => '5'),
-            '1.1'
-        )->willReturn($this->getMockBuilder('React\Http\Client\Request')->disableOriginalConstructor()->getMock());
+        $client->expects($this->once())->method('request')->with($this->callback(function (RequestInterface $request) {
+            return $request->getHeaderLine('Content-Length') === '5';
+        }))->willReturn($this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock());
 
         $sender = new Sender($client);
 
@@ -87,12 +84,9 @@ public function testSendPostWillAutomaticallySendContentLengthHeader()
     public function testSendPostWillAutomaticallySendContentLengthZeroHeaderForEmptyRequestBody()
     {
         $client = $this->getMockBuilder('React\Http\Client\Client')->disableOriginalConstructor()->getMock();
-        $client->expects($this->once())->method('request')->with(
-            'POST',
-            'http://www.google.com/',
-            array('Host' => 'www.google.com', 'Content-Length' => '0'),
-            '1.1'
-        )->willReturn($this->getMockBuilder('React\Http\Client\Request')->disableOriginalConstructor()->getMock());
+        $client->expects($this->once())->method('request')->with($this->callback(function (RequestInterface $request) {
+            return $request->getHeaderLine('Content-Length') === '0';
+        }))->willReturn($this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock());
 
         $sender = new Sender($client);
 
@@ -102,16 +96,13 @@ public function testSendPostWillAutomaticallySendContentLengthZeroHeaderForEmpty
 
     public function testSendPostStreamWillAutomaticallySendTransferEncodingChunked()
     {
-        $outgoing = $this->getMockBuilder('React\Http\Client\Request')->disableOriginalConstructor()->getMock();
+        $outgoing = $this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock();
         $outgoing->expects($this->once())->method('write')->with("");
 
         $client = $this->getMockBuilder('React\Http\Client\Client')->disableOriginalConstructor()->getMock();
-        $client->expects($this->once())->method('request')->with(
-            'POST',
-            'http://www.google.com/',
-            array('Host' => 'www.google.com', 'Transfer-Encoding' => 'chunked'),
-            '1.1'
-        )->willReturn($outgoing);
+        $client->expects($this->once())->method('request')->with($this->callback(function (RequestInterface $request) {
+            return $request->getHeaderLine('Transfer-Encoding') === 'chunked';
+        }))->willReturn($outgoing);
 
         $sender = new Sender($client);
 
@@ -122,7 +113,7 @@ public function testSendPostStreamWillAutomaticallySendTransferEncodingChunked()
 
     public function testSendPostStreamWillAutomaticallyPipeChunkEncodeBodyForWriteAndRespectRequestThrottling()
     {
-        $outgoing = $this->getMockBuilder('React\Http\Client\Request')->disableOriginalConstructor()->getMock();
+        $outgoing = $this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock();
         $outgoing->expects($this->once())->method('isWritable')->willReturn(true);
         $outgoing->expects($this->exactly(2))->method('write')->withConsecutive(array(""), array("5\r\nhello\r\n"))->willReturn(false);
 
@@ -141,7 +132,7 @@ public function testSendPostStreamWillAutomaticallyPipeChunkEncodeBodyForWriteAn
 
     public function testSendPostStreamWillAutomaticallyPipeChunkEncodeBodyForEnd()
     {
-        $outgoing = $this->getMockBuilder('React\Http\Client\Request')->disableOriginalConstructor()->getMock();
+        $outgoing = $this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock();
         $outgoing->expects($this->once())->method('isWritable')->willReturn(true);
         $outgoing->expects($this->exactly(2))->method('write')->withConsecutive(array(""), array("0\r\n\r\n"))->willReturn(false);
         $outgoing->expects($this->once())->method('end')->with(null);
@@ -160,7 +151,7 @@ public function testSendPostStreamWillAutomaticallyPipeChunkEncodeBodyForEnd()
 
     public function testSendPostStreamWillRejectWhenRequestBodyEmitsErrorEvent()
     {
-        $outgoing = $this->getMockBuilder('React\Http\Client\Request')->disableOriginalConstructor()->getMock();
+        $outgoing = $this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock();
         $outgoing->expects($this->once())->method('isWritable')->willReturn(true);
         $outgoing->expects($this->once())->method('write')->with("")->willReturn(false);
         $outgoing->expects($this->never())->method('end');
@@ -190,7 +181,7 @@ public function testSendPostStreamWillRejectWhenRequestBodyEmitsErrorEvent()
 
     public function testSendPostStreamWillRejectWhenRequestBodyClosesWithoutEnd()
     {
-        $outgoing = $this->getMockBuilder('React\Http\Client\Request')->disableOriginalConstructor()->getMock();
+        $outgoing = $this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock();
         $outgoing->expects($this->once())->method('isWritable')->willReturn(true);
         $outgoing->expects($this->once())->method('write')->with("")->willReturn(false);
         $outgoing->expects($this->never())->method('end');
@@ -218,7 +209,7 @@ public function testSendPostStreamWillRejectWhenRequestBodyClosesWithoutEnd()
 
     public function testSendPostStreamWillNotRejectWhenRequestBodyClosesAfterEnd()
     {
-        $outgoing = $this->getMockBuilder('React\Http\Client\Request')->disableOriginalConstructor()->getMock();
+        $outgoing = $this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock();
         $outgoing->expects($this->once())->method('isWritable')->willReturn(true);
         $outgoing->expects($this->exactly(2))->method('write')->withConsecutive(array(""), array("0\r\n\r\n"))->willReturn(false);
         $outgoing->expects($this->once())->method('end');
@@ -247,12 +238,9 @@ public function testSendPostStreamWillNotRejectWhenRequestBodyClosesAfterEnd()
     public function testSendPostStreamWithExplicitContentLengthWillSendHeaderAsIs()
     {
         $client = $this->getMockBuilder('React\Http\Client\Client')->disableOriginalConstructor()->getMock();
-        $client->expects($this->once())->method('request')->with(
-            'POST',
-            'http://www.google.com/',
-            array('Host' => 'www.google.com', 'Content-Length' => '100'),
-            '1.1'
-        )->willReturn($this->getMockBuilder('React\Http\Client\Request')->disableOriginalConstructor()->getMock());
+        $client->expects($this->once())->method('request')->with($this->callback(function (RequestInterface $request) {
+            return $request->getHeaderLine('Content-Length') === '100';
+        }))->willReturn($this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock());
 
         $sender = new Sender($client);
 
@@ -264,12 +252,9 @@ public function testSendPostStreamWithExplicitContentLengthWillSendHeaderAsIs()
     public function testSendGetWillNotPassContentLengthHeaderForEmptyRequestBody()
     {
         $client = $this->getMockBuilder('React\Http\Client\Client')->disableOriginalConstructor()->getMock();
-        $client->expects($this->once())->method('request')->with(
-            'GET',
-            'http://www.google.com/',
-            array('Host' => 'www.google.com'),
-            '1.1'
-        )->willReturn($this->getMockBuilder('React\Http\Client\Request')->disableOriginalConstructor()->getMock());
+        $client->expects($this->once())->method('request')->with($this->callback(function (RequestInterface $request) {
+            return !$request->hasHeader('Content-Length');
+        }))->willReturn($this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock());
 
         $sender = new Sender($client);
 
@@ -280,12 +265,9 @@ public function testSendGetWillNotPassContentLengthHeaderForEmptyRequestBody()
     public function testSendCustomMethodWillNotPassContentLengthHeaderForEmptyRequestBody()
     {
         $client = $this->getMockBuilder('React\Http\Client\Client')->disableOriginalConstructor()->getMock();
-        $client->expects($this->once())->method('request')->with(
-            'CUSTOM',
-            'http://www.google.com/',
-            array('Host' => 'www.google.com'),
-            '1.1'
-        )->willReturn($this->getMockBuilder('React\Http\Client\Request')->disableOriginalConstructor()->getMock());
+        $client->expects($this->once())->method('request')->with($this->callback(function (RequestInterface $request) {
+            return !$request->hasHeader('Content-Length');
+        }))->willReturn($this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock());
 
         $sender = new Sender($client);
 
@@ -296,12 +278,9 @@ public function testSendCustomMethodWillNotPassContentLengthHeaderForEmptyReques
     public function testSendCustomMethodWithExplicitContentLengthZeroWillBePassedAsIs()
     {
         $client = $this->getMockBuilder('React\Http\Client\Client')->disableOriginalConstructor()->getMock();
-        $client->expects($this->once())->method('request')->with(
-            'CUSTOM',
-            'http://www.google.com/',
-            array('Host' => 'www.google.com', 'Content-Length' => '0'),
-            '1.1'
-        )->willReturn($this->getMockBuilder('React\Http\Client\Request')->disableOriginalConstructor()->getMock());
+        $client->expects($this->once())->method('request')->with($this->callback(function (RequestInterface $request) {
+            return $request->getHeaderLine('Content-Length') === '0';
+        }))->willReturn($this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock());
 
         $sender = new Sender($client);
 
@@ -309,6 +288,76 @@ public function testSendCustomMethodWithExplicitContentLengthZeroWillBePassedAsI
         $sender->send($request);
     }
 
+    /** @test */
+    public function getHttp10RequestShouldSendAGetRequestWithoutConnectionHeaderByDefault()
+    {
+        $client = $this->getMockBuilder('React\Http\Client\Client')->disableOriginalConstructor()->getMock();
+        $client->expects($this->once())->method('request')->with($this->callback(function (RequestInterface $request) {
+            return !$request->hasHeader('Connection');
+        }))->willReturn($this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock());
+
+        $sender = new Sender($client);
+
+        $request = new Request('GET', 'http://www.example.com', array(), '', '1.0');
+        $sender->send($request);
+    }
+
+    /** @test */
+    public function getHttp11RequestShouldSendAGetRequestWithConnectionCloseHeaderByDefault()
+    {
+        $client = $this->getMockBuilder('React\Http\Client\Client')->disableOriginalConstructor()->getMock();
+        $client->expects($this->once())->method('request')->with($this->callback(function (RequestInterface $request) {
+            return $request->getHeaderLine('Connection') === 'close';
+        }))->willReturn($this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock());
+
+        $sender = new Sender($client);
+
+        $request = new Request('GET', 'http://www.example.com', array(), '', '1.1');
+        $sender->send($request);
+    }
+
+    /** @test */
+    public function getHttp11RequestShouldSendAGetRequestWithGivenConnectionUpgradeHeader()
+    {
+        $client = $this->getMockBuilder('React\Http\Client\Client')->disableOriginalConstructor()->getMock();
+        $client->expects($this->once())->method('request')->with($this->callback(function (RequestInterface $request) {
+            return $request->getHeaderLine('Connection') === 'upgrade';
+        }))->willReturn($this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock());
+
+        $sender = new Sender($client);
+
+        $request = new Request('GET', 'http://www.example.com', array('Connection' => 'upgrade'), '', '1.1');
+        $sender->send($request);
+    }
+
+    /** @test */
+    public function getRequestWithUserAndPassShouldSendAGetRequestWithBasicAuthorizationHeader()
+    {
+        $client = $this->getMockBuilder('React\Http\Client\Client')->disableOriginalConstructor()->getMock();
+        $client->expects($this->once())->method('request')->with($this->callback(function (RequestInterface $request) {
+            return $request->getHeaderLine('Authorization') === 'Basic am9objpkdW1teQ==';
+        }))->willReturn($this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock());
+
+        $sender = new Sender($client);
+
+        $request = new Request('GET', 'http://john:dummy@www.example.com');
+        $sender->send($request);
+    }
+
+    /** @test */
+    public function getRequestWithUserAndPassShouldSendAGetRequestWithGivenAuthorizationHeaderBasicAuthorizationHeader()
+    {
+        $client = $this->getMockBuilder('React\Http\Client\Client')->disableOriginalConstructor()->getMock();
+        $client->expects($this->once())->method('request')->with($this->callback(function (RequestInterface $request) {
+            return $request->getHeaderLine('Authorization') === 'bearer abc123';
+        }))->willReturn($this->getMockBuilder('React\Http\Io\ClientRequestStream')->disableOriginalConstructor()->getMock());
+
+        $sender = new Sender($client);
+
+        $request = new Request('GET', 'http://john:dummy@www.example.com', array('Authorization' => 'bearer abc123'));
+        $sender->send($request);
+    }
+
     public function testCancelRequestWillCancelConnector()
     {
         $promise = new \React\Promise\Promise(function () { }, function () {
@@ -355,54 +404,4 @@ public function testCancelRequestWillCloseConnection()
 
         $this->assertInstanceOf('RuntimeException', $exception);
     }
-
-    public function provideRequestProtocolVersion()
-    {
-        return array(
-            array(
-                new Request('GET', 'http://www.google.com/'),
-                'GET',
-                'http://www.google.com/',
-                array(
-                    'Host' => 'www.google.com',
-                ),
-                '1.1',
-            ),
-            array(
-                new Request('GET', 'http://www.google.com/', array(), '', '1.0'),
-                'GET',
-                'http://www.google.com/',
-                array(
-                    'Host' => 'www.google.com',
-                ),
-                '1.0',
-            ),
-        );
-    }
-
-    /**
-     * @dataProvider provideRequestProtocolVersion
-     */
-    public function testRequestProtocolVersion(Request $Request, $method, $uri, $headers, $protocolVersion)
-    {
-        $http = $this->getMockBuilder('React\Http\Client\Client')
-                    ->setMethods(array(
-                        'request',
-                    ))
-                    ->setConstructorArgs(array(
-                        $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock(),
-                    ))->getMock();
-
-        $request = $this->getMockBuilder('React\Http\Client\Request')
-                        ->setMethods(array())
-                        ->setConstructorArgs(array(
-                            $this->getMockBuilder('React\Socket\ConnectorInterface')->getMock(),
-                            new RequestData($method, $uri, $headers, $protocolVersion),
-                        ))->getMock();
-
-        $http->expects($this->once())->method('request')->with($method, $uri, $headers, $protocolVersion)->willReturn($request);
-
-        $sender = new Sender($http);
-        $sender->send($Request);
-    }
 }