diff --git a/composer.json b/composer.json
index 1dffae6b..22aec387 100644
--- a/composer.json
+++ b/composer.json
@@ -27,12 +27,13 @@
     }
   , "require": {
         "php": ">=5.4.2"
-      , "ratchet/rfc6455": "^0.3.1"
+      , "ratchet/rfc6455": "^0.4.0"
       , "react/socket": "^1.0 || ^0.8 || ^0.7 || ^0.6 || ^0.5"
       , "react/event-loop": ">=0.4"
       , "guzzlehttp/psr7": "^1.7|^2.0"
-      , "symfony/http-foundation": "^2.6|^3.0|^4.0|^5.0|^6.0"
-      , "symfony/routing": "^2.6|^3.0|^4.0|^5.0|^6.0"
+      , "nyholm/psr7": "^1.8"
+      , "symfony/http-foundation": "^2.6|^3.0|^4.0|^5.0|^6.0|^7.0"
+      , "symfony/routing": "^2.6|^3.0|^4.0|^5.0|^6.0|^7.0"
     }
   , "require-dev": {
         "phpunit/phpunit": "~4.8"
diff --git a/src/Ratchet/WebSocket/WsServer.php b/src/Ratchet/WebSocket/WsServer.php
index 27795ca7..72ba049d 100644
--- a/src/Ratchet/WebSocket/WsServer.php
+++ b/src/Ratchet/WebSocket/WsServer.php
@@ -1,5 +1,6 @@
 <?php
 namespace Ratchet\WebSocket;
+use Nyholm\Psr7\Factory\Psr17Factory;
 use Ratchet\ComponentInterface;
 use Ratchet\ConnectionInterface;
 use Ratchet\MessageComponentInterface as DataComponentInterface;
@@ -86,7 +87,7 @@ public function __construct(ComponentInterface $component) {
         $this->connections = new \SplObjectStorage;
 
         $this->closeFrameChecker   = new CloseFrameChecker;
-        $this->handshakeNegotiator = new ServerNegotiator(new RequestVerifier);
+        $this->handshakeNegotiator = new ServerNegotiator(new RequestVerifier, new Psr17Factory());
         $this->handshakeNegotiator->setStrictSubProtocolCheck(true);
 
         if ($component instanceof WsServerInterface) {