diff --git a/src/stream/Response.php b/src/stream/Response.php
index b617e39..87f2184 100644
--- a/src/stream/Response.php
+++ b/src/stream/Response.php
@@ -27,6 +27,8 @@ class Response extends AbstractResponse
 
     protected $reasonPhrase;
 
+    protected $version;
+
     public function __construct(Request $request, $rawData, array $rawHeaders)
     {
         $this->request = $request;