diff --git a/composer.json b/composer.json
index b3fc3cd..c8507af 100644
--- a/composer.json
+++ b/composer.json
@@ -15,23 +15,24 @@
             "homepage": "https://careers.jobcloud.ch/en/our-team/?term=133"
         }
     ],
-    "config": {
-        "sort-packages": true
-    },
     "require": {
         "php": ">=7.4",
         "ext-json": "*",
-        "pimple/pimple": "^3.2",
-        "symfony/cache": "^5.0",
-        "nyholm/psr7": "^1.2",
-        "kriswallsmith/buzz": "^1.0",
-        "psr/http-message": "^1.0"
+        "psr/http-message": "^1.0",
+        "psr/http-client": "^1.0.1"
     },
     "require-dev": {
-        "squizlabs/php_codesniffer": "^3.4.2",
-        "phpunit/phpunit": "^9.5",
+        "infection/infection": "^0.21",
+        "kriswallsmith/buzz": "^1.0",
+        "nyholm/psr7": "^1.2",
+        "php-mock/php-mock-phpunit": "^2.6",
         "phpstan/phpstan": "^0.12",
+        "phpunit/phpunit": "^9.5",
+        "pimple/pimple": "^3.2",
         "rregeer/phpunit-coverage-check": "^0.3.1",
-        "infection/infection": "^0.21"
+        "squizlabs/php_codesniffer": "^3.4.2"
+    },
+    "config": {
+        "sort-packages": true
     }
 }
diff --git a/phpunit.xml b/phpunit.xml
index 478d6bf..3dfbd31 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,5 +1,17 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" backupGlobals="false" backupStaticAttributes="false" colors="true" convertErrorsToExceptions="true" convertNoticesToExceptions="true" convertWarningsToExceptions="true" processIsolation="false" stopOnFailure="false" bootstrap="vendor/autoload.php" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd">
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd"
+         backupGlobals="false"
+         backupStaticAttributes="false"
+         colors="true"
+         convertErrorsToExceptions="true"
+         convertNoticesToExceptions="true"
+         convertWarningsToExceptions="true"
+         processIsolation="false"
+         stopOnFailure="false"
+         bootstrap="vendor/autoload.php"
+         executionOrder="random"
+         resolveDependencies="true">
   <coverage>
     <include>
       <directory>src</directory>
diff --git a/src/ServiceProvider/KafkaSchemaRegistryApiClientProvider.php b/src/ServiceProvider/KafkaSchemaRegistryApiClientProvider.php
index 26281ca..d8eef03 100644
--- a/src/ServiceProvider/KafkaSchemaRegistryApiClientProvider.php
+++ b/src/ServiceProvider/KafkaSchemaRegistryApiClientProvider.php
@@ -4,8 +4,11 @@
 
 use Buzz\Client\Curl;
 use Jobcloud\Kafka\SchemaRegistryClient\ErrorHandler;
+use Jobcloud\Kafka\SchemaRegistryClient\ErrorHandlerInterface;
 use Jobcloud\Kafka\SchemaRegistryClient\HttpClient;
+use Jobcloud\Kafka\SchemaRegistryClient\HttpClientInterface;
 use Jobcloud\Kafka\SchemaRegistryClient\KafkaSchemaRegistryApiClient;
+use Jobcloud\Kafka\SchemaRegistryClient\KafkaSchemaRegistryApiClientInterface;
 use LogicException;
 use Nyholm\Psr7\Factory\Psr17Factory;
 use Pimple\Container;
@@ -35,26 +38,26 @@ public function register(Container $container): void
     {
         $this->checkRequiredOffsets($container);
 
-        if (false === isset($container[self::REQUEST_FACTORY])) {
-            $container[self::REQUEST_FACTORY] = static function (Container $container) {
+        if (false === isset($container[self::REQUEST_FACTORY]) && class_exists('Nyholm\Psr7\Factory\Psr17Factory')) {
+            $container[self::REQUEST_FACTORY] = static function (): RequestFactoryInterface {
                 return new Psr17Factory();
             };
         }
 
-        if (false === isset($container[self::CLIENT])) {
-            $container[self::CLIENT] = static function (Container $container) {
+        if (false === isset($container[self::CLIENT]) && class_exists('Buzz\Client\Curl')) {
+            $container[self::CLIENT] = static function (Container $container): ClientInterface {
                 return new Curl($container[self::REQUEST_FACTORY]);
             };
         }
 
         if (false === isset($container[self::ERROR_HANDLER])) {
-            $container[self::ERROR_HANDLER] = static function () {
+            $container[self::ERROR_HANDLER] = static function (): ErrorHandlerInterface {
                 return new ErrorHandler();
             };
         }
 
         if (false === isset($container[self::HTTP_CLIENT])) {
-            $container[self::HTTP_CLIENT] = static function (Container $container) {
+            $container[self::HTTP_CLIENT] = static function (Container $container): HttpClientInterface {
                 /** @var ClientInterface $client */
                 $client = $container[self::CLIENT];
 
@@ -73,7 +76,9 @@ public function register(Container $container): void
         }
 
         if (false === isset($container[self::API_CLIENT])) {
-            $container[self::API_CLIENT] = static function (Container $container) {
+            $container[self::API_CLIENT] = static function (
+                Container $container
+            ): KafkaSchemaRegistryApiClientInterface {
                 /** @var HttpClient $client */
                 $client = $container[self::HTTP_CLIENT];
 
@@ -84,7 +89,6 @@ public function register(Container $container): void
 
     private function checkRequiredOffsets(Container $container): void
     {
-
         if (false === isset($container[self::CONTAINER_KEY][self::SETTING_KEY_BASE_URL])) {
             throw new LogicException(
                 sprintf(
diff --git a/tests/KafkaSchemaRegistryApiClientProviderTest.php b/tests/KafkaSchemaRegistryApiClientProviderTest.php
index 61f0c82..32067ab 100644
--- a/tests/KafkaSchemaRegistryApiClientProviderTest.php
+++ b/tests/KafkaSchemaRegistryApiClientProviderTest.php
@@ -7,6 +7,9 @@
 use Jobcloud\Kafka\SchemaRegistryClient\KafkaSchemaRegistryApiClientInterface;
 use Jobcloud\Kafka\SchemaRegistryClient\ServiceProvider\KafkaSchemaRegistryApiClientProvider;
 use LogicException;
+use phpmock\phpunit\MockObjectProxy;
+use phpmock\phpunit\PHPMock;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Pimple\Container;
 use Psr\Http\Message\RequestFactoryInterface;
@@ -16,10 +19,32 @@
  */
 class KafkaSchemaRegistryApiClientProviderTest extends TestCase
 {
+    use PHPMock;
     use ReflectionAccessTrait;
 
+    /**
+     * @var MockObject|MockObjectProxy
+     */
+    private $classExistsMock;
+
+    protected function setUp(): void
+    {
+        parent::setUp(); // TODO: Change the autogenerated stub
+
+        $this->classExistsMock = $this->getFunctionMock(
+            'Jobcloud\Kafka\SchemaRegistryClient\ServiceProvider',
+            'class_exists'
+        );
+    }
+
+
     public function testDefaultContainersAndServicesSetWithMinimalConfig(): void
     {
+        $this->classExistsMock->expects(self::exactly(2))->withConsecutive(
+            ['Nyholm\Psr7\Factory\Psr17Factory'],
+            ['Buzz\Client\Curl']
+        )->willReturn(true);
+
         $container = new Container();
 
         self::assertArrayNotHasKey('kafka.schema.registry', $container);
@@ -62,6 +87,11 @@ public function testDefaultContainersAndServicesSetWithMinimalConfig(): void
 
     public function testSuccessWithMissingAuth(): void
     {
+        $this->classExistsMock->expects(self::exactly(2))->withConsecutive(
+            ['Nyholm\Psr7\Factory\Psr17Factory'],
+            ['Buzz\Client\Curl']
+        )->willReturn(true);
+
         $container = new Container();
 
         $container['kafka.schema.registry'] = [
@@ -83,6 +113,8 @@ public function testSuccessWithMissingAuth(): void
 
     public function testFailOnMissingBaseUrlInContainer(): void
     {
+        $this->classExistsMock->expects(self::never());
+
         $container = new Container();
 
         $container['kafka.schema.registry'] = [
@@ -98,6 +130,11 @@ public function testFailOnMissingBaseUrlInContainer(): void
 
     public function testUserNameAndPasswordFromSettingsArePassedToHttpClient(): void
     {
+        $this->classExistsMock->expects(self::exactly(2))->withConsecutive(
+            ['Nyholm\Psr7\Factory\Psr17Factory'],
+            ['Buzz\Client\Curl']
+        )->willReturn(true);
+
         $container = new Container();
 
         $container['kafka.schema.registry'] = [