From a4c6bb885a87be3dd93e8201c0487752b140ab42 Mon Sep 17 00:00:00 2001
From: VojtaB <triplkrypl@centrum.cz>
Date: Sat, 13 Jun 2026 14:15:13 +0200
Subject: [PATCH] fix wrong type send to withHeader PSR response method

---
 src/Handshake/ServerNegotiator.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Handshake/ServerNegotiator.php b/src/Handshake/ServerNegotiator.php
index 94f0549..656c7d9 100644
--- a/src/Handshake/ServerNegotiator.php
+++ b/src/Handshake/ServerNegotiator.php
@@ -79,7 +79,7 @@ public function handshake(RequestInterface $request): ResponseInterface {
         $upgradeResponse = $response
             ->withHeader('Connection'           , 'Upgrade')
             ->withHeader('Upgrade'              , 'websocket')
-            ->withHeader('Sec-WebSocket-Version', $this->getVersionNumber());
+            ->withHeader('Sec-WebSocket-Version', (string)$this->getVersionNumber());
 
         if (count($this->_supportedSubProtocols) > 0) {
             $upgradeResponse = $upgradeResponse->withHeader(