diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
new file mode 100644
index 0000000..4be7bbd
--- /dev/null
+++ b/.github/workflows/tests.yml
@@ -0,0 +1,42 @@
+name: tests
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  linux_tests:
+    runs-on: ubuntu-20.04
+
+    strategy:
+      matrix:
+        php: ['8.1', '8.2']
+        stability: ['prefer-lowest', 'prefer-stable']
+
+    name: PHP ${{ matrix.php }} - ${{ matrix.stability }}
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          tools: composer:v2
+          coverage: none
+
+      - name: Check for syntax errors in PHP files
+        run: find ./ -type f -name '*.php' -print0 | xargs -0 -L1 -P4 -- php -l
+
+      - name: Check composer files
+        run:  composer validate --strict
+
+      - name: Install dependencies
+        run: composer update --${{ matrix.stability }} --prefer-dist --no-interaction --no-progress
+
+      - name: Execute tests
+        run: vendor/bin/phpunit --verbose
+
+      - name: Check coding standard
+        run: vendor/bin/php-cs-fixer --no-interaction --dry-run --diff -v fix lib/
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index 987e2a2..fe8f41c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,5 @@
 composer.lock
 vendor
+/.phpunit.cache
+/.phpunit.result.cache
+/.php-cs-fixer.cache
diff --git a/composer.json b/composer.json
index 63e9f5f..eb654b9 100644
--- a/composer.json
+++ b/composer.json
@@ -3,7 +3,7 @@
     "description": "A PHP client to use the Ticketpark API",
     "type": "library",
     "require": {
-        "php": ">=5.6",
+        "php": ">=8.1",
         "kriswallsmith/buzz": "^0.15.0"
     },
     "license": "MIT",
@@ -15,6 +15,14 @@
     ],
     "minimum-stability": "stable",
     "autoload": {
-        "psr-4": { "Ticketpark\\ApiClient\\": "lib/ApiClient" }
+        "psr-4": {
+            "Ticketpark\\ApiClient\\": "lib/ApiClient",
+            "Ticketpark\\ApiClient\\Test\\": "test/ApiClient"
+        }
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^9.6",
+        "rector/rector": "^0.18.3",
+        "friendsofphp/php-cs-fixer": "^3.27"
     }
 }
diff --git a/lib/ApiClient/Exception/TokenGenerationException.php b/lib/ApiClient/Exception/TokenGenerationException.php
index deda847..4996d4f 100644
--- a/lib/ApiClient/Exception/TokenGenerationException.php
+++ b/lib/ApiClient/Exception/TokenGenerationException.php
@@ -4,5 +4,4 @@
 
 class TokenGenerationException extends \Exception
 {
-
-}
\ No newline at end of file
+}
diff --git a/lib/ApiClient/TicketparkApiClient.php b/lib/ApiClient/TicketparkApiClient.php
index 3ee1c8d..ab80970 100644
--- a/lib/ApiClient/TicketparkApiClient.php
+++ b/lib/ApiClient/TicketparkApiClient.php
@@ -3,192 +3,80 @@
 namespace Ticketpark\ApiClient;
 
 use Buzz\Browser;
+use Buzz\Client\Curl;
+use Buzz\Message\Response;
 use Ticketpark\ApiClient\Exception\TokenGenerationException;
 use Ticketpark\ApiClient\Token\AccessToken;
 use Ticketpark\ApiClient\Token\RefreshToken;
 
 class TicketparkApiClient
 {
-    /**
-     * @const string ROOT_URL
-     */
-    const ROOT_URL = 'https://api.ticketpark.ch';
-
-    /**
-     * @const int REFRESH_TOKEN_LIFETIME
-     */
-    const REFRESH_TOKEN_LIFETIME = 30 * 86400;
-
-    /**
-     * @var string $apiKey
-     */
-    protected $apiKey;
-
-    /**
-     * @var string $apiSecret
-     */
-    protected $apiSecret;
-
-    /**
-     * @var string $username
-     */
-    protected $username;
-
-    /**
-     * @var string $password
-     */
-    protected $password;
-
-    /**
-     * @var Browser
-     */
-    protected $browser;
-
-    /**
-     * @var RefreshToken
-     */
-    protected $refreshToken;
-
-    /**
-     * @var AccessToken
-     */
-    protected $accessToken;
-
-    /**
-     * Constructor
-     *
-     * @param string $apiKey
-     * @param string $apiSecret
-     */
-    public function __construct($apiKey, $apiSecret)
-    {
-        $this->apiKey = $apiKey;
-        $this->apiSecret = $apiSecret;
+    private const ROOT_URL = 'https://api.ticketpark.ch';
+    private const REFRESH_TOKEN_LIFETIME = 30 * 86400;
+
+    private ?string $username = null;
+    private ?string $password = null;
+    private ?Browser $browser = null;
+    private ?RefreshToken $refreshToken = null;
+    private ?AccessToken $accessToken = null;
+
+    public function __construct(
+        private readonly string $apiKey,
+        private readonly string $apiSecret
+    ) {
     }
 
-    /**
-     * Set browser
-     *
-     * @param Browser $browser
-     * @return $this
-     */
-    public function setBrowser(Browser $browser = null)
+    public function setBrowser(Browser $browser = null): void
     {
         $this->browser = $browser;
-
-        return $this;
     }
 
-    /**
-     * Get browser
-     *
-     * @return \Buzz\Browser
-     */
-    public function getBrowser()
+    public function getBrowser(): Browser
     {
-        if (null == $this->browser) {
-            $this->browser = new \Buzz\Browser(new \Buzz\Client\Curl());
+        if (null === $this->browser) {
+            $this->browser = new Browser(new Curl());
         }
 
         return $this->browser;
     }
 
-    /**
-     * Set user credentials
-     *
-     * @param string $username
-     * @param string $password
-     */
-    public function setUserCredentials($username, $password)
+    public function setUserCredentials(string $username, string $password): void
     {
         $this->username = $username;
         $this->password = $password;
-
-        return $this;
     }
 
-    /**
-     * Get access token
-     *
-     * @return AccessToken
-     */
-    public function getAccessToken()
+    public function getAccessToken(): ?AccessToken
     {
         return $this->accessToken;
     }
 
-    /**
-     * Set access token object
-     *
-     * @param AccessToken $accessToken
-     * @return $this
-     */
-    public function setAccessTokenInstance(AccessToken $accessToken)
+    public function setAccessTokenInstance(AccessToken $accessToken): void
     {
         $this->accessToken = $accessToken;
-
-        return $this;
     }
 
-    /**
-     * Set access token
-     *
-     * @param string $accessToken
-     * @return $this
-     */
-    public function setAccessToken($accessToken)
+    public function setAccessToken(string $accessToken): void
     {
         $this->accessToken = new AccessToken($accessToken);
-
-        return $this;
     }
 
-    /**
-     * Get refresh token
-     *
-     * @return RefreshToken
-     */
-    public function getRefreshToken()
+    public function getRefreshToken(): ?RefreshToken
     {
         return $this->refreshToken;
     }
 
-    /**
-     * Set refresh token object
-     *
-     * @param RefreshToken $refreshToken
-     * @return $this
-     */
-    public function setRefreshTokenInstance(RefreshToken $refreshToken)
+    public function setRefreshTokenInstance(RefreshToken $refreshToken): void
     {
         $this->refreshToken = $refreshToken;
-
-        return $this;
     }
 
-
-    /**
-     * Set refresh token
-     *
-     * @param RefreshToken $refreshToken
-     * @return $this
-     */
-    public function setRefreshToken($refreshToken)
+    public function setRefreshToken(string $refreshToken): void
     {
         $this->refreshToken = new RefreshToken($refreshToken);
-
-        return $this;
     }
 
-    /**
-     * GET
-     *
-     * @param string $path
-     * @param array $parameters
-     * @param array $headers
-     * @return \Buzz\Message\Response
-     */
-    public function get($path, $parameters = array(), $headers = array())
+    public function get(string $path, array $parameters = [], array $headers = []): Response
     {
         $params = '';
         if (count($parameters)) {
@@ -198,27 +86,12 @@ public function get($path, $parameters = array(), $headers = array())
         return $this->getBrowser()->get(self::ROOT_URL . $path . $params, $this->getDefaultHeaders($headers));
     }
 
-    /**
-     * POST
-     *
-     * @param string $path
-     * @param string $content
-     * @param array $headers
-     * @return \Buzz\Message\Response
-     */
-    public function post($path, $content = '', $headers = array())
+    public function post(string $path, string $content = '', array $headers = []): Response
     {
-        return $this->getBrowser()->post(self::ROOT_URL . $path, $this->getDefaultHeaders($headers), json_encode($content));
+        return $this->getBrowser()->post(self::ROOT_URL . $path, $this->getDefaultHeaders($headers), json_encode($content, JSON_THROW_ON_ERROR));
     }
 
-    /**
-     * HEAD
-     *
-     * @param string $path
-     * @param array $headers
-     * @return \Buzz\Message\Response
-     */
-    public function head($path, $parameters = array(), $headers = array())
+    public function head($path, array $parameters = [], array $headers = []): Response
     {
         $params = '';
         if (count($parameters)) {
@@ -228,58 +101,25 @@ public function head($path, $parameters = array(), $headers = array())
         return $this->getBrowser()->head(self::ROOT_URL . $path . $params, $this->getDefaultHeaders($headers));
     }
 
-    /**
-     * PATCH
-     *
-     * @param string $path
-     * @param string $content
-     * @param array $headers
-     * @return \Buzz\Message\Response
-     */
-    public function patch($path, $content = '', $headers = array())
+    public function patch(string $path, string $content = '', array $headers = []): Response
     {
-        return $this->getBrowser()->patch(self::ROOT_URL . $path, $this->getDefaultHeaders($headers), json_encode($content));
+        return $this->getBrowser()->patch(self::ROOT_URL . $path, $this->getDefaultHeaders($headers), json_encode($content, JSON_THROW_ON_ERROR));
     }
 
-    /**
-     * PUT
-     *
-     * @param string $path
-     * @param string $content
-     * @param array $headers
-     * @return \Buzz\Message\MessageInterface
-     */
-    public function put($path, $content = '', $headers = array())
-    {
-        return $this->getBrowser()->put(self::ROOT_URL . $path, $this->getDefaultHeaders($headers), json_encode($content));
-    }
-
-    /**
-     * DELETE
-     *
-     * @param string $path
-     * @param array $headers
-     * @return \Buzz\Message\Response
-     */
-    public function delete($path, $headers = array())
+    public function delete(string $path, array $headers = []): Response
     {
         return $this->getBrowser()->delete(self::ROOT_URL . $path, $this->getDefaultHeaders($headers));
     }
 
-    /**
-     * Generate new tokens
-     *
-     * @throws TokenGenerationException
-     */
-    public function generateTokens()
+    public function generateTokens(): void
     {
         // Try with refresh token
         $refreshToken = $this->getRefreshToken();
         if ($refreshToken && !$refreshToken->hasExpired()) {
-            $data = array(
+            $data = [
                 'refresh_token' => $refreshToken->getToken(),
                 'grant_type' => 'refresh_token'
-            );
+            ];
 
             if ($this->doGenerateTokens($data)) {
                 return;
@@ -288,11 +128,11 @@ public function generateTokens()
 
         // Try with user credentials
         if (!isset($data) && $this->username) {
-            $data = array(
+            $data = [
                 'username' => $this->username,
                 'password' => $this->password,
                 'grant_type' => 'password'
-            );
+            ];
 
             if ($this->doGenerateTokens($data)) {
                 return;
@@ -302,28 +142,14 @@ public function generateTokens()
         throw new TokenGenerationException('Failed to generate a access tokens. Make sure to provide a valid refresh token or user credentials.');
     }
 
-    /**
-     * Get headers
-     *
-     * @return array
-     */
-    protected function getDefaultHeaders($customHeaders = array())
+    private function getDefaultHeaders(array $customHeaders = []): array
     {
-        $headers = array(
-            'Content-Type' => 'application/json',
-            'Accept' => 'application/json',
-            'Authorization' => 'Bearer ' .  $this->getValidAccessToken()
-        );
+        $headers = ['Content-Type' => 'application/json', 'Accept' => 'application/json', 'Authorization' => 'Bearer ' .  $this->getValidAccessToken()];
 
         return array_merge($customHeaders, $headers);
     }
 
-    /**
-     * Get a valid access token
-     *
-     * @return string
-     */
-    protected function getValidAccessToken()
+    private function getValidAccessToken(): string
     {
         $accessToken = $this->getAccessToken();
 
@@ -335,26 +161,18 @@ protected function getValidAccessToken()
         return $accessToken->getToken();
     }
 
-    /**
-     * Actually tries to generate tokens.
-     *
-     * Returns whether token generation has been successful.
-     *
-     * @param array $data
-     * @return bool
-     */
-    protected function doGenerateTokens(array $data)
+    protected function doGenerateTokens(array $data): bool
     {
-        $headers = array(
+        $headers = [
             'Content-Type'  => 'application/x-www-form-urlencoded',
             'Accept'        => 'application/json',
             'Authorization' => 'Basic '.base64_encode($this->apiKey . ':' . $this->apiSecret)
-        );
+        ];
 
         $response = $this->getBrowser()->post(self::ROOT_URL . '/oauth/v2/token', $headers, $data);
 
         if (200 == $response->getStatusCode()) {
-            $response = json_decode($response->getContent(), true);
+            $response = json_decode((string) $response->getContent(), true, 512, JSON_THROW_ON_ERROR);
 
             $this->accessToken = new AccessToken(
                 $response['access_token'],
@@ -371,4 +189,4 @@ protected function doGenerateTokens(array $data)
 
         return false;
     }
-}
\ No newline at end of file
+}
diff --git a/lib/ApiClient/Token/AccessToken.php b/lib/ApiClient/Token/AccessToken.php
index 84736b7..828921d 100644
--- a/lib/ApiClient/Token/AccessToken.php
+++ b/lib/ApiClient/Token/AccessToken.php
@@ -4,5 +4,4 @@
 
 class AccessToken extends Token
 {
-
-}
\ No newline at end of file
+}
diff --git a/lib/ApiClient/Token/RefreshToken.php b/lib/ApiClient/Token/RefreshToken.php
index 746b51c..d201675 100644
--- a/lib/ApiClient/Token/RefreshToken.php
+++ b/lib/ApiClient/Token/RefreshToken.php
@@ -4,5 +4,4 @@
 
 class RefreshToken extends Token
 {
-
-}
\ No newline at end of file
+}
diff --git a/lib/ApiClient/Token/Token.php b/lib/ApiClient/Token/Token.php
index 45280ae..2c34258 100644
--- a/lib/ApiClient/Token/Token.php
+++ b/lib/ApiClient/Token/Token.php
@@ -4,75 +4,25 @@
 
 abstract class Token
 {
-    /**
-     * Seconds to consider token as expired before it actually expires
-     *
-     * @const int TIMEOUT_BUFFER
-     */
-    const TIMEOUT_BUFFER = 10;
+    private const TIMEOUT_BUFFER = 10;
 
-    /**
-     * @var string $token
-     */
-    protected $token;
-
-    /**
-     * @var \DateTime
-     */
-    protected $expiration;
-
-    /**
-     * @return string
-     */
-    public function getToken()
-    {
-        return $this->token;
-    }
-
-    /**
-     * @param string|null $token
-     * @param \DateTime|null $expiration
-     */
-    public function __construct($token = null, \DateTime $expiration = null)
-    {
-        $this->token = $token;
-        $this->expiration = $expiration;
+    public function __construct(
+        private readonly string $token,
+        private readonly ?\DateTime $expiration = null
+    ) {
     }
 
-    /**
-     * @param string $token
-     * @return Token
-     */
-    public function setToken($token)
+    public function getToken(): string
     {
-        $this->token = $token;
-
-        return $this;
+        return $this->token;
     }
 
-    /**
-     * @return \DateTime
-     */
-    public function getExpiration()
+    public function getExpiration(): ?\DateTime
     {
         return $this->expiration;
     }
 
-    /**
-     * @param \DateTime $expiration
-     * @return Token
-     */
-    public function setExpiration(\DateTime $expiration)
-    {
-        $this->expiration = $expiration;
-
-        return $this;
-    }
-
-    /**
-     * @return bool
-     */
-    public function hasExpired()
+    public function hasExpired(): bool
     {
         if (null == $this->getExpiration()) {
 
@@ -81,4 +31,4 @@ public function hasExpired()
 
         return $this->getExpiration()->getTimestamp() < (time() + self::TIMEOUT_BUFFER);
     }
-}
\ No newline at end of file
+}
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 5984109..2e53e5a 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,9 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-
-<phpunit backupGlobals="false" bootstrap="vendor/autoload.php" colors="true">
-    <testsuites>
-        <testsuite name="Ticketpark Api Client Suite">
-            <directory suffix="Test.php">./test/ApiClient/</directory>
-        </testsuite>
-    </testsuites>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" colors="true" bootstrap="vendor/autoload.php" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.3/phpunit.xsd">
+  <coverage/>
+  <testsuites>
+    <testsuite name="Ticketpark PHP Api Client">
+      <directory>./test</directory>
+    </testsuite>
+  </testsuites>
 </phpunit>
diff --git a/rector.php b/rector.php
new file mode 100644
index 0000000..199185a
--- /dev/null
+++ b/rector.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\Set\ValueObject\LevelSetList;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->paths([
+        __DIR__ . '/lib',
+        __DIR__ . '/test',
+    ]);
+
+    $rectorConfig->sets([
+        LevelSetList::UP_TO_PHP_81
+    ]);
+};
diff --git a/test/ApiClient/TicketparkApiClientTest.php b/test/ApiClient/TicketparkApiClientTest.php
index 7983ea7..7cbe205 100644
--- a/test/ApiClient/TicketparkApiClientTest.php
+++ b/test/ApiClient/TicketparkApiClientTest.php
@@ -2,96 +2,91 @@
 
 namespace Ticketpark\ApiClient\Test;
 
+use Buzz\Browser;
+use Buzz\Message\Response;
+use PHPUnit\Framework\TestCase;
+use Ticketpark\ApiClient\Exception\TokenGenerationException;
 use Ticketpark\ApiClient\TicketparkApiClient;
 use Ticketpark\ApiClient\Token\AccessToken;
 use Ticketpark\ApiClient\Token\RefreshToken;
 
-class TicketparkApiClientTest extends \PHPUnit_Framework_TestCase
+class TicketparkApiClientTest extends TestCase
 {
     protected $apiClient;
 
-    public function setUp()
+    public function setUp(): void
     {
         $this->apiClient = new TicketparkApiClient('apiKey', 'apiSecret');
     }
 
     public function testDefaultBrowser()
     {
-        $this->assertInstanceOf('Buzz\Browser', $this->apiClient->getBrowser());
-    }
-
-    public function testSetValidBrowser()
-    {
-        $this->assertInstanceOf('Ticketpark\ApiClient\TicketparkApiClient', $this->apiClient->setBrowser($this->getBrowserMock()));
-        $this->assertEquals('testBrowser', $this->apiClient->getBrowser()->getTestName());
+        $this->assertInstanceOf(Browser::class, $this->apiClient->getBrowser());
     }
 
     public function testSetAccessToken()
     {
         $this->apiClient->setAccessToken('foo');
-        $this->assertInstanceOf('Ticketpark\ApiClient\Token\AccessToken', $this->apiClient->getAccessToken());
+        $this->assertInstanceOf(AccessToken::class, $this->apiClient->getAccessToken());
         $this->assertEquals('foo', $this->apiClient->getAccessToken()->getToken());
     }
 
     public function testSetAccessTokenInstance()
     {
-        $accessToken = new AccessToken();
-        $accessToken->setToken('bar');
+        $accessToken = new AccessToken('bar');
         $this->apiClient->setAccessTokenInstance($accessToken);
 
-        $this->assertInstanceOf('Ticketpark\ApiClient\Token\AccessToken', $this->apiClient->getAccessToken());
+        $this->assertInstanceOf(AccessToken::class, $this->apiClient->getAccessToken());
         $this->assertEquals('bar', $this->apiClient->getAccessToken()->getToken());
     }
 
     public function testSetRefreshToken()
     {
         $this->apiClient->setRefreshToken('foo');
-        $this->assertInstanceOf('Ticketpark\ApiClient\Token\RefreshToken', $this->apiClient->getRefreshToken());
+        $this->assertInstanceOf(RefreshToken::class, $this->apiClient->getRefreshToken());
         $this->assertEquals('foo', $this->apiClient->getRefreshToken()->getToken());
     }
 
     public function testSetRefreshTokenInstance()
     {
-        $refreshToken = new RefreshToken();
-        $refreshToken->setToken('bar');
+        $refreshToken = new RefreshToken('bar');
         $this->apiClient->setRefreshTokenInstance($refreshToken);
 
-        $this->assertInstanceOf('Ticketpark\ApiClient\Token\RefreshToken', $this->apiClient->getRefreshToken());
+        $this->assertInstanceOf(RefreshToken::class, $this->apiClient->getRefreshToken());
         $this->assertEquals('bar', $this->apiClient->getRefreshToken()->getToken());
     }
 
-    /**
-     * @expectedException  Ticketpark\ApiClient\Exception\TokenGenerationException
-     */
     public function testGenerateTokensWithoutData()
     {
+        $this->expectException(TokenGenerationException::class);
+
         $this->apiClient->generateTokens();
     }
 
     public function testGenerateTokensWithUserCredentials()
     {
-        $this->apiClient->setBrowser($this->getBrowserMock(array(
-            'post' => array(
+        $this->apiClient->setBrowser($this->getBrowserMock([
+            'post' => [
                 'expects' => $this->once(),
-                'with' => array(
+                'with' => [
                     $this->equalTo('https://api.ticketpark.ch/oauth/v2/token'),
                     $this->anything(),
-                    $this->equalTo(array(
+                    $this->equalTo([
                         'username' => 'username',
                         'password' => 'password',
                         'grant_type' => 'password'
-                    )),
-                ),
-                'response' => array(
+                    ]),
+                ],
+                'response' => [
                     'status' => 200,
-                    'content' => array(
+                    'content' => [
                         'access_token' => 'accessToken',
                         'refresh_token' => 'refreshToken',
                         'expires_in' => 60
-                    )
-                )
-            )
-        )));
+                    ]
+                ]
+            ]
+        ]));
 
         $this->apiClient->setUserCredentials('username', 'password');
         $this->apiClient->generateTokens();
@@ -100,29 +95,28 @@ public function testGenerateTokensWithUserCredentials()
         $this->assertEquals('refreshToken', $this->apiClient->getRefreshToken()->getToken());
     }
 
-    /**
-     * @expectedException  Ticketpark\ApiClient\Exception\TokenGenerationException
-     */
     public function testGenerateTokensWithUserCredentialsFails()
     {
-        $this->apiClient->setBrowser($this->getBrowserMock(array(
-            'post' => array(
+        $this->expectException(TokenGenerationException::class);
+
+        $this->apiClient->setBrowser($this->getBrowserMock([
+            'post' => [
                 'expects' => $this->once(),
-                'with' => array(
+                'with' => [
                     $this->equalTo('https://api.ticketpark.ch/oauth/v2/token'),
                     $this->anything(),
-                    $this->equalTo(array(
+                    $this->equalTo([
                         'username' => 'username',
                         'password' => 'password',
                         'grant_type' => 'password'
-                    )),
-                ),
-                'response' => array(
+                    ]),
+                ],
+                'response' => [
                     'status' => 400,
                     'content' => ''
-                )
-            )
-        )));
+                ]
+            ]
+        ]));
 
         $this->apiClient->setUserCredentials('username', 'password');
         $this->apiClient->generateTokens();
@@ -130,27 +124,27 @@ public function testGenerateTokensWithUserCredentialsFails()
 
     public function testGenerateTokensWithRefreshToken()
     {
-        $this->apiClient->setBrowser($this->getBrowserMock(array(
-            'post' => array(
+        $this->apiClient->setBrowser($this->getBrowserMock([
+            'post' => [
                 'expects' => $this->once(),
-                'with' => array(
+                'with' => [
                     $this->equalTo('https://api.ticketpark.ch/oauth/v2/token'),
                     $this->anything(),
-                    $this->equalTo(array(
+                    $this->equalTo([
                         'refresh_token' => 'mySavedRefreshToken',
                         'grant_type' => 'refresh_token'
-                    )),
-                ),
-                'response' => array(
+                    ]),
+                ],
+                'response' => [
                     'status' => 200,
-                    'content' => array(
+                    'content' => [
                         'access_token' => 'accessToken',
                         'refresh_token' => 'refreshToken',
                         'expires_in' => 60
-                    )
-                )
-            )
-        )));
+                    ]
+                ]
+            ]
+        ]));
 
         $this->apiClient->setRefreshToken('mySavedRefreshToken');
         $this->apiClient->generateTokens();
@@ -159,28 +153,27 @@ public function testGenerateTokensWithRefreshToken()
         $this->assertEquals('refreshToken', $this->apiClient->getRefreshToken()->getToken());
     }
 
-    /**
-     * @expectedException  Ticketpark\ApiClient\Exception\TokenGenerationException
-     */
     public function testGenerateTokensWithRefreshTokenFails()
     {
-        $this->apiClient->setBrowser($this->getBrowserMock(array(
-            'post' => array(
+        $this->expectException(TokenGenerationException::class);
+
+        $this->apiClient->setBrowser($this->getBrowserMock([
+            'post' => [
                 'expects' => $this->once(),
-                'with' => array(
+                'with' => [
                     $this->equalTo('https://api.ticketpark.ch/oauth/v2/token'),
                     $this->anything(),
-                    $this->equalTo(array(
+                    $this->equalTo([
                         'refresh_token' => 'mySavedRefreshToken',
                         'grant_type' => 'refresh_token'
-                    )),
-                ),
-                'response' => array(
+                    ]),
+                ],
+                'response' => [
                     'status' => 400,
                     'content' => ''
-                )
-            )
-        )));
+                ]
+            ]
+        ]));
 
         $this->apiClient->setRefreshToken('mySavedRefreshToken');
         $this->apiClient->generateTokens();
@@ -188,173 +181,142 @@ public function testGenerateTokensWithRefreshTokenFails()
 
     public function testGet()
     {
-        $this->apiClient->setBrowser($this->getBrowserMock(array(
-            'get' => array(
+        $this->apiClient->setBrowser($this->getBrowserMock([
+            'get' => [
                 'expects' => $this->once(),
-                'with' => array(
+                'with' => [
                     $this->equalTo('https://api.ticketpark.ch/shows?a=1&b=2&c%5Bd%5D=3'),
-                    $this->equalTo(array(
+                    $this->equalTo([
                         'Content-Type' => 'application/json',
                         'Accept' => 'application/json',
                         'Authorization' => 'Bearer myAccessToken',
                         'CustomHeader' => 'foo'
-                    ))
-                ),
-                'response' => array(
+                    ])
+                ],
+                'response' => [
                     'status' => 200,
                     'content' => ''
-                )
-            ),
+                ]
+            ],
 
-        )));
+        ]));
 
         $this->apiClient->setAccessToken('myAccessToken');
-        $this->apiClient->get('/shows', array('a' => 1, 'b' => 2, 'c' => array('d' => 3)), array('CustomHeader' => 'foo'));
+        $this->apiClient->get('/shows', ['a' => 1, 'b' => 2, 'c' => ['d' => 3]], ['CustomHeader' => 'foo']);
     }
 
     public function testHead()
     {
-        $this->apiClient->setBrowser($this->getBrowserMock(array(
-            'head' => array(
+        $this->apiClient->setBrowser($this->getBrowserMock([
+            'head' => [
                 'expects' => $this->once(),
-                'with' => array(
+                'with' => [
                     $this->equalTo('https://api.ticketpark.ch/shows?a=1&b=2&c%5Bd%5D=3'),
-                    $this->equalTo(array(
+                    $this->equalTo([
                         'Content-Type' => 'application/json',
                         'Accept' => 'application/json',
                         'Authorization' => 'Bearer myAccessToken',
                         'CustomHeader' => 'foo'
-                    ))
-                ),
-                'response' => array(
+                    ])
+                ],
+                'response' => [
                     'status' => 200,
                     'content' => ''
-                )
-            ),
+                ]
+            ],
 
-        )));
+        ]));
 
         $this->apiClient->setAccessToken('myAccessToken');
-        $this->apiClient->head('/shows', array('a' => 1, 'b' => 2, 'c' => array('d' => 3)), array('CustomHeader' => 'foo'));
+        $this->apiClient->head('/shows', ['a' => 1, 'b' => 2, 'c' => ['d' => 3]], ['CustomHeader' => 'foo']);
     }
 
     public function testPatch()
     {
-        $this->apiClient->setBrowser($this->getBrowserMock(array(
-            'patch' => array(
+        $this->apiClient->setBrowser($this->getBrowserMock([
+            'patch' => [
                 'expects' => $this->once(),
-                'with' => array(
+                'with' => [
                     $this->equalTo('https://api.ticketpark.ch/shows/foo'),
-                    $this->equalTo(array(
+                    $this->equalTo([
                         'Content-Type' => 'application/json',
                         'Accept' => 'application/json',
                         'Authorization' => 'Bearer myAccessToken',
                         'CustomHeader' => 'foo'
-                    )),
+                    ]),
                     $this->equalTo('"content"')
-                ),
-                'response' => array(
+                ],
+                'response' => [
                     'status' => 200,
                     'content' => ''
-                )
-            ),
+                ]
+            ],
 
-        )));
+        ]));
 
         $this->apiClient->setAccessToken('myAccessToken');
-        $this->apiClient->patch('/shows/foo', 'content', array('CustomHeader' => 'foo'));
+        $this->apiClient->patch('/shows/foo', 'content', ['CustomHeader' => 'foo']);
     }
 
     public function testPost()
     {
-        $this->apiClient->setBrowser($this->getBrowserMock(array(
-            'post' => array(
-                'expects' => $this->once(),
-                'with' => array(
-                    $this->equalTo('https://api.ticketpark.ch/shows/foo'),
-                    $this->equalTo(array(
-                        'Content-Type' => 'application/json',
-                        'Accept' => 'application/json',
-                        'Authorization' => 'Bearer myAccessToken',
-                        'CustomHeader' => 'foo'
-                    )),
-                    $this->equalTo('"content"')
-                ),
-                'response' => array(
-                    'status' => 200,
-                    'content' => ''
-                )
-            ),
-
-        )));
-
-        $this->apiClient->setAccessToken('myAccessToken');
-        $this->apiClient->post('/shows/foo', 'content', array('CustomHeader' => 'foo'));
-    }
-
-    public function testPut()
-    {
-        $this->apiClient->setBrowser($this->getBrowserMock(array(
-            'put' => array(
+        $this->apiClient->setBrowser($this->getBrowserMock([
+            'post' => [
                 'expects' => $this->once(),
-                'with' => array(
+                'with' => [
                     $this->equalTo('https://api.ticketpark.ch/shows/foo'),
-                    $this->equalTo(array(
+                    $this->equalTo([
                         'Content-Type' => 'application/json',
                         'Accept' => 'application/json',
                         'Authorization' => 'Bearer myAccessToken',
                         'CustomHeader' => 'foo'
-                    )),
+                    ]),
                     $this->equalTo('"content"')
-                ),
-                'response' => array(
+                ],
+                'response' => [
                     'status' => 200,
                     'content' => ''
-                )
-            ),
+                ]
+            ],
 
-        )));
+        ]));
 
         $this->apiClient->setAccessToken('myAccessToken');
-        $this->apiClient->put('/shows/foo', 'content', array('CustomHeader' => 'foo'));
+        $this->apiClient->post('/shows/foo', 'content', ['CustomHeader' => 'foo']);
     }
 
     public function testDelete()
     {
-        $this->apiClient->setBrowser($this->getBrowserMock(array(
-            'delete' => array(
+        $this->apiClient->setBrowser($this->getBrowserMock([
+            'delete' => [
                 'expects' => $this->once(),
-                'with' => array(
+                'with' => [
                     $this->equalTo('https://api.ticketpark.ch/shows/foo'),
-                    $this->equalTo(array(
+                    $this->equalTo([
                         'Content-Type' => 'application/json',
                         'Accept' => 'application/json',
                         'Authorization' => 'Bearer myAccessToken',
                         'CustomHeader' => 'foo'
-                    ))
-                ),
-                'response' => array(
+                    ])
+                ],
+                'response' => [
                     'status' => 200,
                     'content' => ''
-                )
-            ),
+                ]
+            ],
 
-        )));
+        ]));
 
         $this->apiClient->setAccessToken('myAccessToken');
-        $this->apiClient->delete('/shows/foo', array('CustomHeader' => 'foo'));
+        $this->apiClient->delete('/shows/foo', ['CustomHeader' => 'foo']);
     }
 
-    protected function getBrowserMock($data = array())
+    protected function getBrowserMock($data = [])
     {
-        $browser = $this->getMockBuilder('Buzz\Browser')
-            ->setMethods(array('getTestName', 'head', 'get', 'post', 'patch', 'put', 'delete'))
+        $browser = $this->getMockBuilder(Browser::class)
+            ->onlyMethods(['head', 'get', 'post', 'patch', 'delete'])
             ->getMock();
 
-        $browser
-            ->method('getTestName')
-            ->willReturn('testBrowser');
-
         foreach($data as $method => $params) {
             $browser
                 ->expects($params['expects'])
@@ -368,8 +330,8 @@ protected function getBrowserMock($data = array())
 
     protected function getResponseMock($status, $content)
     {
-        $response = $this->getMockBuilder('Buzz\Message\Response')
-            ->setMethods(array('getStatusCode', 'getContent'))
+        $response = $this->getMockBuilder(Response::class)
+            ->onlyMethods(['getStatusCode', 'getContent'])
             ->getMock();
 
         $response
@@ -378,8 +340,8 @@ protected function getResponseMock($status, $content)
 
         $response
             ->method('getContent')
-            ->willReturn(json_encode($content));
+            ->willReturn(json_encode($content, JSON_THROW_ON_ERROR));
 
         return $response;
     }
-}
\ No newline at end of file
+}