diff --git a/Version/Hixie76.php b/Version/Hixie76.php
index 069263a..8b0e2c4 100644
--- a/Version/Hixie76.php
+++ b/Version/Hixie76.php
@@ -23,7 +23,7 @@ class Hixie76 implements VersionInterface {
      * {@inheritdoc}
      */
     public function isProtocol(RequestInterface $request) {
-        return !(null === $request->getHeader('Sec-WebSocket-Key2', true));
+        return !(null === $request->getHeader('Sec-WebSocket-Key2'));
     }
 
     /**
@@ -44,13 +44,13 @@ class Hixie76 implements VersionInterface {
             throw new \UnderflowException("Not enough data received to issue challenge response");
         }
 
-        $challenge = $this->sign($request->getHeader('Sec-WebSocket-Key1', true), $request->getHeader('Sec-WebSocket-Key2', true), $body);
+        $challenge = $this->sign((string)$request->getHeader('Sec-WebSocket-Key1'), (string)$request->getHeader('Sec-WebSocket-Key2'), $body);
 
         $headers = array(
             'Upgrade'                => 'WebSocket'
           , 'Connection'             => 'Upgrade'
-          , 'Sec-WebSocket-Origin'   => $request->getHeader('Origin', true)
-          , 'Sec-WebSocket-Location' => 'ws://' . $request->getHeader('Host', true) . $request->getPath()
+          , 'Sec-WebSocket-Origin'   => (string)$request->getHeader('Origin')
+          , 'Sec-WebSocket-Location' => 'ws://' . (string)$request->getHeader('Host') . $request->getPath()
         );
 
         $response = new Response(101, $headers, $challenge);
diff --git a/Version/HyBi10.php b/Version/HyBi10.php
index 5d89078..70329c6 100644
--- a/Version/HyBi10.php
+++ b/Version/HyBi10.php
@@ -4,7 +4,7 @@ use Guzzle\Http\Message\RequestInterface;
 
 class HyBi10 extends RFC6455 {
     public function isProtocol(RequestInterface $request) {
-        $version = $request->hasHeader('Sec-WebSocket-Version') ? (int)$request->getHeader('Sec-WebSocket-Version', true) : -1;
+        $version = (int)(string)$request->getHeader('Sec-WebSocket-Version');
 
         return ($version >= 6 && $version < 13);
     }
diff --git a/Version/RFC6455.php b/Version/RFC6455.php
index 22a96a0..23e166c 100644
--- a/Version/RFC6455.php
+++ b/Version/RFC6455.php
@@ -50,7 +50,7 @@ class RFC6455 implements VersionInterface {
      * {@inheritdoc}
      */
     public function isProtocol(RequestInterface $request) {
-        $version = $request->hasHeader('Sec-WebSocket-Version') ? (int)$request->getHeader('Sec-WebSocket-Version', true) : -1;
+        $version = (int)(string)$request->getHeader('Sec-WebSocket-Version');
 
         return ($this->getVersionNumber() === $version);
     }
@@ -73,7 +73,7 @@ class RFC6455 implements VersionInterface {
         return new Response(101, array(
             'Upgrade'              => 'websocket'
           , 'Connection'           => 'Upgrade'
-          , 'Sec-WebSocket-Accept' => $this->sign($request->getHeader('Sec-WebSocket-Key', true))
+          , 'Sec-WebSocket-Accept' => $this->sign((string)$request->getHeader('Sec-WebSocket-Key'))
         ));
     }
 
@@ -268,4 +268,4 @@ class RFC6455 implements VersionInterface {
         $this->closeCodes[Frame::CLOSE_SRV_ERR]     = true;
         //$this->closeCodes[Frame::CLOSE_TLS]         = true;
     }
-}
\ No newline at end of file
+}
diff --git a/Version/RFC6455/HandshakeVerifier.php b/Version/RFC6455/HandshakeVerifier.php
index ea17d08..41057cc 100644
--- a/Version/RFC6455/HandshakeVerifier.php
+++ b/Version/RFC6455/HandshakeVerifier.php
@@ -19,10 +19,10 @@ class HandshakeVerifier {
         $passes += (int)$this->verifyMethod($request->getMethod());
         $passes += (int)$this->verifyHTTPVersion($request->getProtocolVersion());
         $passes += (int)$this->verifyRequestURI($request->getPath());
-        $passes += (int)$this->verifyHost($request->getHeader('Host', true));
-        $passes += (int)$this->verifyUpgradeRequest($request->getHeader('Upgrade', true));
-        $passes += (int)$this->verifyConnection($request->getHeader('Connection', true));
-        $passes += (int)$this->verifyKey($request->getHeader('Sec-WebSocket-Key', true));
+        $passes += (int)$this->verifyHost((string)$request->getHeader('Host'));
+        $passes += (int)$this->verifyUpgradeRequest((string)$request->getHeader('Upgrade'));
+        $passes += (int)$this->verifyConnection((string)$request->getHeader('Connection'));
+        $passes += (int)$this->verifyKey((string)$request->getHeader('Sec-WebSocket-Key'));
         //$passes += (int)$this->verifyVersion($headers['Sec-WebSocket-Version']); // Temporarily breaking functionality
 
         return (7 === $passes);
diff --git a/WsServer.php b/WsServer.php
index 0373a14..460e328 100644
--- a/WsServer.php
+++ b/WsServer.php
@@ -111,8 +111,10 @@ class WsServer implements HttpServerInterface {
             return;
         }
 
-        if ('' !== ($agreedSubProtocols = $this->getSubProtocolString($conn->WebSocket->request->getTokenizedHeader('Sec-WebSocket-Protocol', ',')))) {
-            $response->setHeader('Sec-WebSocket-Protocol', $agreedSubProtocols);
+        if (null !== ($subHeader = $conn->WebSocket->request->getHeader('Sec-WebSocket-Protocol'))) {
+            if ('' !== ($agreedSubProtocols = $this->getSubProtocolString($subHeader->normalize()))) {
+                $response->setHeader('Sec-WebSocket-Protocol', $agreedSubProtocols);
+            }
         }
 
         $response->setHeader('X-Powered-By', \Ratchet\VERSION);