diff --git a/Classes/Utility/GuzzleUtility.php b/Classes/Utility/GuzzleUtility.php
index 6e7c0d3..042daaa 100644
--- a/Classes/Utility/GuzzleUtility.php
+++ b/Classes/Utility/GuzzleUtility.php
@@ -5,7 +5,7 @@
 namespace Kanti\ServerTiming\Utility;
 
 use Closure;
-use GuzzleHttp\Promise\FulfilledPromise;
+use GuzzleHttp\Promise\PromiseInterface;
 use Psr\Http\Message\RequestInterface;
 
 class GuzzleUtility
@@ -13,7 +13,7 @@ class GuzzleUtility
     public static function getHandler(): Closure
     {
         return static function (callable $handler): Closure {
-            return static function (RequestInterface $request, array $options) use ($handler): FulfilledPromise {
+            return static function (RequestInterface $request, array $options) use ($handler): PromiseInterface {
                 $info = $request->getMethod() . ' ' . $request->getUri()->__toString();
                 $stop = TimingUtility::stopWatch('guzzle', $info);
                 $response = $handler($request, $options);