diff --git a/composer.json b/composer.json
index e432783..eab4b6e 100644
--- a/composer.json
+++ b/composer.json
@@ -26,8 +26,8 @@
         "ext-iconv": "*",
         "php-http/client-implementation": "^1.0",
         "php-http/httplug": "^1.0|^2.0",
-        "php-http/message-factory": "^1.0",
-        "psr/http-message": "^1.0"
+        "psr/http-message": "^2.0",
+        "psr/http-factory": "^1.0"
     },
     "require-dev": {
         "phpmd/phpmd": "^2.9.1",
@@ -40,5 +40,11 @@
         "php-parallel-lint/php-parallel-lint": "^1.2",
         "egulias/email-validator": "^2.1.23",
         "symfony/mailer": "^5.0"
+    },
+    "config": {
+        "allow-plugins": {
+            "php-http/discovery": true,
+            "dealerdirect/phpcodesniffer-composer-installer": true
+        }
     }
 }
diff --git a/src/MailhogClient.php b/src/MailhogClient.php
index c77abbf..79375bd 100644
--- a/src/MailhogClient.php
+++ b/src/MailhogClient.php
@@ -1,11 +1,13 @@
 <?php
+
 declare(strict_types=1);
 
 namespace rpkamp\Mailhog;
 
 use Generator;
-use Http\Client\HttpClient;
-use Http\Message\RequestFactory;
+use Psr\Http\Client\ClientInterface;
+use Psr\Http\Message\RequestFactoryInterface;
+use Psr\Http\Message\StreamFactoryInterface;
 use rpkamp\Mailhog\Message\Message;
 use rpkamp\Mailhog\Message\MessageFactory;
 use rpkamp\Mailhog\Specification\Specification;
@@ -22,24 +24,34 @@
 class MailhogClient
 {
     /**
-     * @var HttpClient
+     * @var ClientInterface
      */
     private $httpClient;
 
     /**
-     * @var RequestFactory
+     * @var RequestFactoryInterface
      */
     private $requestFactory;
 
+    /**
+     * @var StreamFactoryInterface
+     */
+    private $streamFactory;
+
     /**
      * @var string
      */
     private $baseUri;
 
-    public function __construct(HttpClient $client, RequestFactory $requestFactory, string $baseUri)
-    {
+    public function __construct(
+        ClientInterface $client,
+        RequestFactoryInterface $requestFactory,
+        StreamFactoryInterface $streamFactory,
+        string $baseUri
+    ) {
         $this->httpClient = $client;
         $this->requestFactory = $requestFactory;
+        $this->streamFactory = $streamFactory;
         $this->baseUri = rtrim($baseUri, '/');
     }
 
@@ -165,12 +177,10 @@ public function releaseMessage(string $messageId, string $host, int $port, strin
 
         $request = $this->requestFactory->createRequest(
             'POST',
-            sprintf('%s/api/v1/messages/%s/release', $this->baseUri, $messageId),
-            [],
-            $body
+            sprintf('%s/api/v1/messages/%s/release', $this->baseUri, $messageId)
         );
 
-        $this->httpClient->sendRequest($request);
+        $this->httpClient->sendRequest($request->withBody($this->streamFactory->createStream($body)));
     }
 
     public function getMessageById(string $messageId): Message
diff --git a/tests/integration/MailhogClientTest.php b/tests/integration/MailhogClientTest.php
index 9502c0f..aaef645 100644
--- a/tests/integration/MailhogClientTest.php
+++ b/tests/integration/MailhogClientTest.php
@@ -5,7 +5,7 @@
 
 use Generator;
 use Http\Client\Curl\Client;
-use Nyholm\Psr7\Factory\HttplugFactory;
+use Nyholm\Psr7\Factory\Psr17Factory;
 use PHPUnit\Framework\TestCase;
 use rpkamp\Mailhog\MailhogClient;
 use rpkamp\Mailhog\Message\Mime\Attachment;
@@ -35,7 +35,12 @@ class MailhogClientTest extends TestCase
 
     public function setUp(): void
     {
-        $this->client = new MailhogClient(new Client(), new HttplugFactory(), $_ENV['mailhog_api_uri']);
+        $this->client = new MailhogClient(
+            new Client(),
+            new Psr17Factory(),
+            new Psr17Factory(),
+            $_ENV['mailhog_api_uri']
+        );
         $this->client->purgeMessages();
     }
 
diff --git a/tests/unit/MailhogClientTest.php b/tests/unit/MailhogClientTest.php
index a5fb721..02e0617 100644
--- a/tests/unit/MailhogClientTest.php
+++ b/tests/unit/MailhogClientTest.php
@@ -1,10 +1,11 @@
 <?php
+
 declare(strict_types=1);
 
 namespace rpkamp\Mailhog\Tests\unit;
 
 use Http\Client\Curl\Client;
-use Http\Message\MessageFactory\GuzzleMessageFactory;
+use Nyholm\Psr7\Factory\Psr17Factory;
 use PHPUnit\Framework\TestCase;
 use ReflectionProperty;
 use rpkamp\Mailhog\MailhogClient;
@@ -16,7 +17,7 @@ final class MailhogClientTest extends TestCase
      */
     public function it_should_remove_trailing_slashes_from_base_uri(): void
     {
-        $client = new MailhogClient(new Client(), new GuzzleMessageFactory(), 'http://mailhog/');
+        $client = new MailhogClient(new Client(), new Psr17Factory(), new Psr17Factory(), 'http://mailhog/');
 
         $property = new ReflectionProperty($client, 'baseUri');
         $property->setAccessible(true);