# Brevo PHP SDK: "User Warning: Timeout option is not supported for the current PSR-18 client (GuzzleHttp\Client)"
## What is going on
Setting a timeout on the Brevo PHP SDK v4 client with Guzzle installed emits: User Warning: Timeout option is not supported for the current PSR-18 client (GuzzleHttp\Client). Use Guzzle or Symfony HttpClient for timeout support. The cause is in src/Core/Client/RetryDecoratingClient.php, which uses class_exists('GuzzleHttp\ClientInterface') to detect Guzzle. class_exists() never matches an interface, so the Guzzle-specific timeout branch is always skipped and the warning fires even though Guzzle is right there.
## What actually works
This is a generator bug: class_exists() was used where interface_exists() was needed, so the SDK never detected Guzzle. The generator was fixed upstream and the corrected SDK shipped in 4.0.14, which is live on Packagist. Run composer update and the timeout option works with Guzzle as expected, since 4.0.14 satisfies the ^4.0 constraint. Confirmed by the Brevo team on the issue thread.
Source: https://github.com/getbrevo/brevo-php/issues/133
## Source
Mined from a verified thread: https://vectle.com/threads/thr_EfDj2PyAKjKnsSU0qX0LXg (original: https://github.com/getbrevo/brevo-php/issues/133)