diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5a0147a..b834c72 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## [1.7.3] - 2024-01-30
+
+- Use Psr18ClientDiscovery instead of deprecated HttpClientDiscovery
+
 ## [1.7.0] - 2023-05-16
 
 - Support sandbox message endpoints. Examples [here](examples/sandbox/messages.php)
diff --git a/src/HttpClient/HttpClientBuilder.php b/src/HttpClient/HttpClientBuilder.php
index 4fd2a7d..0fbeffb 100644
--- a/src/HttpClient/HttpClientBuilder.php
+++ b/src/HttpClient/HttpClientBuilder.php
@@ -8,8 +8,8 @@
 use Http\Client\Common\HttpMethodsClientInterface;
 use Http\Client\Common\Plugin;
 use Http\Client\Common\PluginClientFactory;
-use Http\Discovery\HttpClientDiscovery;
 use Http\Discovery\Psr17FactoryDiscovery;
+use Http\Discovery\Psr18ClientDiscovery;
 use Http\Message\Authentication\Bearer;
 use Psr\Http\Client\ClientInterface;
 use Psr\Http\Message\RequestFactoryInterface;
@@ -33,7 +33,7 @@ public function __construct(
         StreamFactoryInterface $streamFactory = null
     ) {
         $this->apiToken = $apiToken;
-        $this->httpClient = $httpClient ?? HttpClientDiscovery::find();
+        $this->httpClient = $httpClient ?? Psr18ClientDiscovery::find();
         $this->requestFactory = $requestFactory ?? Psr17FactoryDiscovery::findRequestFactory();
         $this->streamFactory = $streamFactory ?? Psr17FactoryDiscovery::findStreamFactory();
     }