diff --git a/src/ClientFactory.php b/src/ClientFactory.php
index cdf6799..338ae41 100644
--- a/src/ClientFactory.php
+++ b/src/ClientFactory.php
@@ -39,7 +39,7 @@ public function __invoke(ContainerInterface $container)
             ->withBaseUri($baseUri)
             ->withApiKey($apiKey)
             ->withOrganization($organization)
-            ->withHttpHeader('OpenAI-Beta', 'assistants=v1')
+            ->withHttpHeader('OpenAI-Beta', 'assistants=v2')
             ->withHttpClient($httpClient)
             ->make();
     }