diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 4313121..0e0b2eb 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -4,8 +4,6 @@ on:
   push:
     branches: [master]
   pull_request:
-  schedule:
-    - cron: '39 2 * * 0'
 
 jobs:
   tests:
@@ -19,17 +17,15 @@ jobs:
         ports:
           - 2025:2025
           - 9025:9025
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-22.04
     name: Test
     strategy:
       fail-fast: false
       matrix:
         php: ["7.2", "7.3", "7.4", "8.0"]
         composer-flags: ["", "--prefer-lowest"]
-
     env:
       COMPOSER_ROOT_VERSION: dev-master
-
     steps:
       - uses: actions/checkout@v2
 
@@ -37,10 +33,10 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: "${{ matrix.php }}"
+          coverage: pcov
 
       - name: Install dependencies
         run: composer update ${{ matrix.composer-flags }}
 
       - name: Run tests
         run: make test
-
diff --git a/Makefile b/Makefile
index 32ce63a..7ebd738 100644
--- a/Makefile
+++ b/Makefile
@@ -16,16 +16,16 @@ code-style: phpmd phpcs
 phpmd:
 	vendor/bin/phpmd src/ xml phpmd.xml --suffixes php
 
-# Check code adheres to PSR-2
+# Check if code adheres to PSR-2
 phpcs:
 	vendor/bin/phpcs
 
 # Run unit tests
 unit-tests:
 ifeq ($(CI),true)
-	vendor/bin/phpunit --testdox -v --coverage-clover=coverage.xml
+	vendor/bin/phpunit --coverage-clover=coverage.xml
 else
-	vendor/bin/phpunit --testdox -v
+	vendor/bin/phpunit
 endif
 
 phpstan:
diff --git a/composer.json b/composer.json
index eab4b6e..5f84878 100644
--- a/composer.json
+++ b/composer.json
@@ -25,13 +25,13 @@
         "ext-json": "*",
         "ext-iconv": "*",
         "php-http/client-implementation": "^1.0",
-        "php-http/httplug": "^1.0|^2.0",
-        "psr/http-message": "^2.0",
+        "php-http/httplug": "^1.0 || ^2.0",
+        "psr/http-message": "^1.0 || ^2.0",
         "psr/http-factory": "^1.0"
     },
     "require-dev": {
         "phpmd/phpmd": "^2.9.1",
-        "phpunit/phpunit": "^8.0",
+        "phpunit/phpunit": "^8.0 || ^9.0 || ^10.0",
         "php-http/curl-client": "^2.0",
         "phpstan/phpstan": "^0.12.64",
         "pdepend/pdepend": "^2.5",
diff --git a/src/MailhogClient.php b/src/MailhogClient.php
index 79375bd..af31ff0 100644
--- a/src/MailhogClient.php
+++ b/src/MailhogClient.php
@@ -7,6 +7,7 @@
 use Generator;
 use Psr\Http\Client\ClientInterface;
 use Psr\Http\Message\RequestFactoryInterface;
+use Psr\Http\Message\RequestInterface;
 use Psr\Http\Message\StreamFactoryInterface;
 use rpkamp\Mailhog\Message\Message;
 use rpkamp\Mailhog\Message\MessageFactory;
@@ -14,6 +15,7 @@
 use RuntimeException;
 
 use function array_filter;
+use function assert;
 use function count;
 use function iterator_to_array;
 use function json_decode;
@@ -178,9 +180,16 @@ public function releaseMessage(string $messageId, string $host, int $port, strin
         $request = $this->requestFactory->createRequest(
             'POST',
             sprintf('%s/api/v1/messages/%s/release', $this->baseUri, $messageId)
-        );
+        )->withBody($this->streamFactory->createStream($body));
+
+        /**
+         * Help PHPStan see that this is actually a RequestInterface. withBody is a method
+         * on MessageInterface and has return type MessageInterface in version 1.0 of psr/http-message.
+         * This has been fixed in version 2.0 of psr/http-message where the return type is `static`.
+         */
+        assert($request instanceof RequestInterface);
 
-        $this->httpClient->sendRequest($request->withBody($this->streamFactory->createStream($body)));
+        $this->httpClient->sendRequest($request);
     }
 
     public function getMessageById(string $messageId): Message