diff --git a/.travis.yml b/.travis.yml
index 454b8284..2684cac3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,19 +5,23 @@ sudo: false
 
 cache:
   directories:
-  - vendor
+    - vendor
+
+env:
+  - DEPENDENCIES=""
+  - DEPENDENCIES="--prefer-lowest --prefer-stable"
 
 php:
-  - 5.6
   - 7.0
   - 7.1
   - 7.2
 
 install:
-  - travis_retry composer install --no-interaction --prefer-source
+  - composer update --no-interaction --prefer-dist $DEPENDENCIES
 
 script:
   - vendor/bin/phpunit
+  - vendor/bin/phpstan analyse -l 6 -c phpstan.neon src tests
 
 branches:
   only:
diff --git a/composer.json b/composer.json
index d8d11125..8e7fd7e6 100644
--- a/composer.json
+++ b/composer.json
@@ -4,17 +4,20 @@
     "homepage": "https://oauth2.thephpleague.com/",
     "license": "MIT",
     "require": {
-        "php": ">=5.6.0",
+        "php": ">=7.0.0",
         "ext-openssl": "*",
         "league/event": "^2.1",
-        "lcobucci/jwt": "^3.1",
+        "lcobucci/jwt": "^3.2.2",
         "paragonie/random_compat": "^2.0",
-        "psr/http-message": "^1.0",
+        "psr/http-message": "^1.0.1",
         "defuse/php-encryption": "^2.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4.8.38 || ^5.7.21",
-        "zendframework/zend-diactoros": "^1.0"
+        "phpunit/phpunit": "^6.3 || ^7.0",
+        "zendframework/zend-diactoros": "^1.3.2",
+        "phpstan/phpstan": "^0.9.2",
+        "phpstan/phpstan-phpunit": "^0.9.4",
+        "phpstan/phpstan-strict-rules": "^0.9.0"
     },
     "repositories": [
         {
diff --git a/examples/public/api.php b/examples/public/api.php
index 3032ffed..2f896434 100644
--- a/examples/public/api.php
+++ b/examples/public/api.php
@@ -49,16 +49,18 @@ $app->get(
             ],
         ];
 
+        $totalUsers = count($users);
+
         // If the access token doesn't have the `basic` scope hide users' names
         if (in_array('basic', $request->getAttribute('oauth_scopes')) === false) {
-            for ($i = 0; $i < count($users); $i++) {
+            for ($i = 0; $i < $totalUsers; $i++) {
                 unset($users[$i]['name']);
             }
         }
 
         // If the access token doesn't have the `email` scope hide users' email addresses
         if (in_array('email', $request->getAttribute('oauth_scopes')) === false) {
-            for ($i = 0; $i < count($users); $i++) {
+            for ($i = 0; $i < $totalUsers; $i++) {
                 unset($users[$i]['email']);
             }
         }
diff --git a/examples/public/implicit.php b/examples/public/implicit.php
index 73de09ec..73e46e46 100644
--- a/examples/public/implicit.php
+++ b/examples/public/implicit.php
@@ -41,7 +41,6 @@ $app = new App([
             $privateKeyPath,
             'lxZFUEsBCJ2Yb14IF2ygAHI5N4+ZAUXXaSeeJm6+twsUmIen'
         );
-        $server->setEncryptionKey('lxZFUEsBCJ2Yb14IF2ygAHI5N4+ZAUXXaSeeJm6+twsUmIen');
 
         // Enable the implicit grant on the server with a token TTL of 1 hour
         $server->enableGrantType(new ImplicitGrant(new \DateInterval('PT1H')));
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 00000000..88c21d40
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,5 @@
+includes:
+	- vendor/phpstan/phpstan-phpunit/extension.neon
+	- vendor/phpstan/phpstan-phpunit/rules.neon
+	- vendor/phpstan/phpstan-phpunit/strictRules.neon
+	- vendor/phpstan/phpstan-strict-rules/rules.neon
diff --git a/src/AuthorizationServer.php b/src/AuthorizationServer.php
index 69c16954..885776ec 100644
--- a/src/AuthorizationServer.php
+++ b/src/AuthorizationServer.php
@@ -17,6 +17,7 @@ use League\OAuth2\Server\Repositories\AccessTokenRepositoryInterface;
 use League\OAuth2\Server\Repositories\ClientRepositoryInterface;
 use League\OAuth2\Server\Repositories\ScopeRepositoryInterface;
 use League\OAuth2\Server\RequestTypes\AuthorizationRequest;
+use League\OAuth2\Server\ResponseTypes\AbstractResponseType;
 use League\OAuth2\Server\ResponseTypes\BearerTokenResponse;
 use League\OAuth2\Server\ResponseTypes\ResponseTypeInterface;
 use Psr\Http\Message\ResponseInterface;
@@ -190,7 +191,6 @@ class AuthorizationServer implements EmitterAwareInterface
             if ($tokenResponse instanceof ResponseTypeInterface) {
                 return $tokenResponse->generateHttpResponse($response);
             }
-            
         }
 
         throw OAuthServerException::unsupportedGrantType();
@@ -207,7 +207,9 @@ class AuthorizationServer implements EmitterAwareInterface
             $this->responseType = new BearerTokenResponse();
         }
 
-        $this->responseType->setPrivateKey($this->privateKey);
+        if ($this->responseType instanceof AbstractResponseType === true) {
+            $this->responseType->setPrivateKey($this->privateKey);
+        }
         $this->responseType->setEncryptionKey($this->encryptionKey);
 
         return $this->responseType;
diff --git a/src/CryptKey.php b/src/CryptKey.php
index 0d5f5cf6..efc5f5e8 100644
--- a/src/CryptKey.php
+++ b/src/CryptKey.php
@@ -48,9 +48,9 @@ class CryptKey
         if ($keyPermissionsCheck === true) {
             // Verify the permissions of the key
             $keyPathPerms = decoct(fileperms($keyPath) & 0777);
-            if (in_array($keyPathPerms, ['600', '660'], true) === false) {
+            if (in_array($keyPathPerms, ['400', '440', '600', '660'], true) === false) {
                 trigger_error(sprintf(
-                    'Key file "%s" permissions are not correct, should be 600 or 660 instead of %s',
+                    'Key file "%s" permissions are not correct, recommend changing to 600 or 660 instead of %s',
                     $keyPath,
                     $keyPathPerms
                 ), E_USER_NOTICE);
@@ -73,7 +73,11 @@ class CryptKey
         $tmpDir = sys_get_temp_dir();
         $keyPath = $tmpDir . '/' . sha1($key) . '.key';
 
-        if (!file_exists($keyPath) && !touch($keyPath)) {
+        if (file_exists($keyPath)) {
+            return 'file://' . $keyPath;
+        }
+
+        if (!touch($keyPath)) {
             // @codeCoverageIgnoreStart
             throw new \RuntimeException(sprintf('"%s" key file could not be created', $keyPath));
             // @codeCoverageIgnoreEnd
diff --git a/src/Entities/AccessTokenEntityInterface.php b/src/Entities/AccessTokenEntityInterface.php
index c297e267..4da7600e 100644
--- a/src/Entities/AccessTokenEntityInterface.php
+++ b/src/Entities/AccessTokenEntityInterface.php
@@ -9,6 +9,7 @@
 
 namespace League\OAuth2\Server\Entities;
 
+use Lcobucci\JWT\Token;
 use League\OAuth2\Server\CryptKey;
 
 interface AccessTokenEntityInterface extends TokenInterface
@@ -18,7 +19,7 @@ interface AccessTokenEntityInterface extends TokenInterface
      *
      * @param CryptKey $privateKey
      *
-     * @return string
+     * @return Token
      */
     public function convertToJWT(CryptKey $privateKey);
 }
diff --git a/src/Entities/RefreshTokenEntityInterface.php b/src/Entities/RefreshTokenEntityInterface.php
index 05e86e00..e4f10400 100644
--- a/src/Entities/RefreshTokenEntityInterface.php
+++ b/src/Entities/RefreshTokenEntityInterface.php
@@ -21,7 +21,7 @@ interface RefreshTokenEntityInterface
     /**
      * Set the token's identifier.
      *
-     * @param $identifier
+     * @param mixed $identifier
      */
     public function setIdentifier($identifier);
 
diff --git a/src/Entities/TokenInterface.php b/src/Entities/TokenInterface.php
index c842b09a..378adbdc 100644
--- a/src/Entities/TokenInterface.php
+++ b/src/Entities/TokenInterface.php
@@ -21,7 +21,7 @@ interface TokenInterface
     /**
      * Set the token's identifier.
      *
-     * @param $identifier
+     * @param mixed $identifier
      */
     public function setIdentifier($identifier);
 
@@ -42,14 +42,14 @@ interface TokenInterface
     /**
      * Set the identifier of the user associated with the token.
      *
-     * @param string|int $identifier The identifier of the user
+     * @param string|int|null $identifier The identifier of the user
      */
     public function setUserIdentifier($identifier);
 
     /**
      * Get the token user's identifier.
      *
-     * @return string|int
+     * @return string|int|null
      */
     public function getUserIdentifier();
 
diff --git a/src/Entities/Traits/AccessTokenTrait.php b/src/Entities/Traits/AccessTokenTrait.php
index 741d6c19..81fc1bfd 100644
--- a/src/Entities/Traits/AccessTokenTrait.php
+++ b/src/Entities/Traits/AccessTokenTrait.php
@@ -12,6 +12,7 @@ namespace League\OAuth2\Server\Entities\Traits;
 use Lcobucci\JWT\Builder;
 use Lcobucci\JWT\Signer\Key;
 use Lcobucci\JWT\Signer\Rsa\Sha256;
+use Lcobucci\JWT\Token;
 use League\OAuth2\Server\CryptKey;
 use League\OAuth2\Server\Entities\ClientEntityInterface;
 use League\OAuth2\Server\Entities\ScopeEntityInterface;
@@ -23,7 +24,7 @@ trait AccessTokenTrait
      *
      * @param CryptKey $privateKey
      *
-     * @return string
+     * @return Token
      */
     public function convertToJWT(CryptKey $privateKey)
     {
diff --git a/src/Entities/Traits/EntityTrait.php b/src/Entities/Traits/EntityTrait.php
index 20c86591..05452923 100644
--- a/src/Entities/Traits/EntityTrait.php
+++ b/src/Entities/Traits/EntityTrait.php
@@ -11,7 +11,7 @@ namespace League\OAuth2\Server\Entities\Traits;
 
 trait EntityTrait
 {
-    /*
+    /**
      * @var string
      */
     protected $identifier;
diff --git a/src/Entities/Traits/TokenEntityTrait.php b/src/Entities/Traits/TokenEntityTrait.php
index 0b5608cd..c6653cce 100644
--- a/src/Entities/Traits/TokenEntityTrait.php
+++ b/src/Entities/Traits/TokenEntityTrait.php
@@ -25,7 +25,7 @@ trait TokenEntityTrait
     protected $expiryDateTime;
 
     /**
-     * @var string|int
+     * @var string|int|null
      */
     protected $userIdentifier;
 
@@ -77,7 +77,7 @@ trait TokenEntityTrait
     /**
      * Set the identifier of the user associated with the token.
      *
-     * @param string|int $identifier The identifier of the user
+     * @param string|int|null $identifier The identifier of the user
      */
     public function setUserIdentifier($identifier)
     {
@@ -87,7 +87,7 @@ trait TokenEntityTrait
     /**
      * Get the token user's identifier.
      *
-     * @return string|int
+     * @return string|int|null
      */
     public function getUserIdentifier()
     {
diff --git a/src/Exception/OAuthServerException.php b/src/Exception/OAuthServerException.php
index 8d101c4c..b67bcf03 100644
--- a/src/Exception/OAuthServerException.php
+++ b/src/Exception/OAuthServerException.php
@@ -33,6 +33,11 @@ class OAuthServerException extends \Exception
      */
     private $redirectUri;
 
+    /**
+     * @var array
+     */
+    private $payload;
+
     /**
      * Throw a new exception.
      *
@@ -50,6 +55,33 @@ class OAuthServerException extends \Exception
         $this->errorType = $errorType;
         $this->hint = $hint;
         $this->redirectUri = $redirectUri;
+        $this->payload = [
+            'error'   => $errorType,
+            'message' => $message,
+        ];
+        if ($hint !== null) {
+            $this->payload['hint'] = $hint;
+        }
+    }
+
+    /**
+     * Returns the current payload.
+     *
+     * @return array
+     */
+    public function getPayload()
+    {
+        return $this->payload;
+    }
+
+    /**
+     * Updates the current payload.
+     *
+     * @param array $payload
+     */
+    public function setPayload(array $payload)
+    {
+        $this->payload = $payload;
     }
 
     /**
@@ -131,7 +163,7 @@ class OAuthServerException extends \Exception
     /**
      * Server error.
      *
-     * @param $hint
+     * @param string $hint
      *
      * @return static
      *
@@ -213,21 +245,15 @@ class OAuthServerException extends \Exception
      *
      * @param ResponseInterface $response
      * @param bool              $useFragment True if errors should be in the URI fragment instead of query string
+     * @param int               $jsonOptions options passed to json_encode
      *
      * @return ResponseInterface
      */
-    public function generateHttpResponse(ResponseInterface $response, $useFragment = false)
+    public function generateHttpResponse(ResponseInterface $response, $useFragment = false, $jsonOptions = 0)
     {
         $headers = $this->getHttpHeaders();
 
-        $payload = [
-            'error'   => $this->getErrorType(),
-            'message' => $this->getMessage(),
-        ];
-
-        if ($this->hint !== null) {
-            $payload['hint'] = $this->hint;
-        }
+        $payload = $this->getPayload();
 
         if ($this->redirectUri !== null) {
             if ($useFragment === true) {
@@ -243,7 +269,7 @@ class OAuthServerException extends \Exception
             $response = $response->withHeader($header, $content);
         }
 
-        $response->getBody()->write(json_encode($payload));
+        $response->getBody()->write(json_encode($payload, $jsonOptions));
 
         return $response->withStatus($this->getHttpStatusCode());
     }
diff --git a/src/Grant/AbstractGrant.php b/src/Grant/AbstractGrant.php
index 25378955..304ba99b 100644
--- a/src/Grant/AbstractGrant.php
+++ b/src/Grant/AbstractGrant.php
@@ -204,7 +204,7 @@ abstract class AbstractGrant implements GrantTypeInterface
                 throw OAuthServerException::invalidClient();
             } elseif (
                 is_array($client->getRedirectUri())
-                && in_array($redirectUri, $client->getRedirectUri()) === false
+                && in_array($redirectUri, $client->getRedirectUri(), true) === false
             ) {
                 $this->getEmitter()->emit(new RequestEvent(RequestEvent::CLIENT_AUTHENTICATION_FAILED, $request));
                 throw OAuthServerException::invalidClient();
@@ -341,7 +341,7 @@ abstract class AbstractGrant implements GrantTypeInterface
      *
      * @param \DateInterval          $accessTokenTTL
      * @param ClientEntityInterface  $client
-     * @param string                 $userIdentifier
+     * @param string|null            $userIdentifier
      * @param ScopeEntityInterface[] $scopes
      *
      * @throws OAuthServerException
diff --git a/src/Grant/AuthCodeGrant.php b/src/Grant/AuthCodeGrant.php
index 122edf00..d1669b2f 100644
--- a/src/Grant/AuthCodeGrant.php
+++ b/src/Grant/AuthCodeGrant.php
@@ -244,23 +244,24 @@ class AuthCodeGrant extends AbstractAuthorizeGrant
                 throw OAuthServerException::invalidClient();
             } elseif (
                 is_array($client->getRedirectUri())
-                && in_array($redirectUri, $client->getRedirectUri()) === false
+                && in_array($redirectUri, $client->getRedirectUri(), true) === false
             ) {
                 $this->getEmitter()->emit(new RequestEvent(RequestEvent::CLIENT_AUTHENTICATION_FAILED, $request));
                 throw OAuthServerException::invalidClient();
             }
         } elseif (is_array($client->getRedirectUri()) && count($client->getRedirectUri()) !== 1
-            || empty($client->getRedirectUri())
-        ) {
+            || empty($client->getRedirectUri())) {
             $this->getEmitter()->emit(new RequestEvent(RequestEvent::CLIENT_AUTHENTICATION_FAILED, $request));
             throw OAuthServerException::invalidClient();
+        } else {
+            $redirectUri = is_array($client->getRedirectUri())
+                ? $client->getRedirectUri()[0]
+                : $client->getRedirectUri();
         }
 
         $scopes = $this->validateScopes(
             $this->getQueryStringParameter('scope', $request, $this->defaultScope),
-            is_array($client->getRedirectUri())
-                ? $client->getRedirectUri()[0]
-                : $client->getRedirectUri()
+            $redirectUri
         );
 
         $stateParameter = $this->getQueryStringParameter('state', $request);
@@ -279,7 +280,7 @@ class AuthCodeGrant extends AbstractAuthorizeGrant
             }
 
             $codeChallengeMethod = $this->getQueryStringParameter('code_challenge_method', $request, 'plain');
-            if (in_array($codeChallengeMethod, ['plain', 'S256']) === false) {
+            if (in_array($codeChallengeMethod, ['plain', 'S256'], true) === false) {
                 throw OAuthServerException::invalidRequest(
                     'code_challenge_method',
                     'Code challenge method must be `plain` or `S256`'
diff --git a/src/Grant/ImplicitGrant.php b/src/Grant/ImplicitGrant.php
index f3c9e694..19e3e684 100644
--- a/src/Grant/ImplicitGrant.php
+++ b/src/Grant/ImplicitGrant.php
@@ -33,7 +33,7 @@ class ImplicitGrant extends AbstractAuthorizeGrant
 
     /**
      * @param \DateInterval $accessTokenTTL
-     * @param string $queryDelimiter
+     * @param string        $queryDelimiter
      */
     public function __construct(\DateInterval $accessTokenTTL, $queryDelimiter = '#')
     {
@@ -144,23 +144,24 @@ class ImplicitGrant extends AbstractAuthorizeGrant
                 throw OAuthServerException::invalidClient();
             } elseif (
                 is_array($client->getRedirectUri())
-                && in_array($redirectUri, $client->getRedirectUri()) === false
+                && in_array($redirectUri, $client->getRedirectUri(), true) === false
             ) {
                 $this->getEmitter()->emit(new RequestEvent(RequestEvent::CLIENT_AUTHENTICATION_FAILED, $request));
                 throw OAuthServerException::invalidClient();
             }
         } elseif (is_array($client->getRedirectUri()) && count($client->getRedirectUri()) !== 1
-            || empty($client->getRedirectUri())
-        ) {
+            || empty($client->getRedirectUri())) {
             $this->getEmitter()->emit(new RequestEvent(RequestEvent::CLIENT_AUTHENTICATION_FAILED, $request));
             throw OAuthServerException::invalidClient();
+        } else {
+            $redirectUri = is_array($client->getRedirectUri())
+                ? $client->getRedirectUri()[0]
+                : $client->getRedirectUri();
         }
 
         $scopes = $this->validateScopes(
             $this->getQueryStringParameter('scope', $request, $this->defaultScope),
-            is_array($client->getRedirectUri())
-                ? $client->getRedirectUri()[0]
-                : $client->getRedirectUri()
+            $redirectUri
         );
 
         // Finalize the requested scopes
diff --git a/src/Grant/RefreshTokenGrant.php b/src/Grant/RefreshTokenGrant.php
index 66a3b266..f8e022b4 100644
--- a/src/Grant/RefreshTokenGrant.php
+++ b/src/Grant/RefreshTokenGrant.php
@@ -11,7 +11,6 @@
 
 namespace League\OAuth2\Server\Grant;
 
-use League\OAuth2\Server\Entities\ScopeEntityInterface;
 use League\OAuth2\Server\Exception\OAuthServerException;
 use League\OAuth2\Server\Repositories\RefreshTokenRepositoryInterface;
 use League\OAuth2\Server\RequestEvent;
@@ -53,7 +52,7 @@ class RefreshTokenGrant extends AbstractGrant
         // The OAuth spec says that a refreshed access token can have the original scopes or fewer so ensure
         // the request doesn't include any new scopes
         foreach ($scopes as $scope) {
-            if (in_array($scope->getIdentifier(), $oldRefreshToken['scopes']) === false) {
+            if (in_array($scope->getIdentifier(), $oldRefreshToken['scopes'], true) === false) {
                 throw OAuthServerException::invalidScope($scope->getIdentifier());
             }
         }
diff --git a/src/Repositories/ClientRepositoryInterface.php b/src/Repositories/ClientRepositoryInterface.php
index 34adf56a..ba0610d5 100644
--- a/src/Repositories/ClientRepositoryInterface.php
+++ b/src/Repositories/ClientRepositoryInterface.php
@@ -20,12 +20,12 @@ interface ClientRepositoryInterface extends RepositoryInterface
      * Get a client.
      *
      * @param string      $clientIdentifier   The client's identifier
-     * @param string      $grantType          The grant type used
+     * @param null|string $grantType          The grant type used (if sent)
      * @param null|string $clientSecret       The client's secret (if sent)
      * @param bool        $mustValidateSecret If true the client must attempt to validate the secret if the client
      *                                        is confidential
      *
      * @return ClientEntityInterface
      */
-    public function getClientEntity($clientIdentifier, $grantType, $clientSecret = null, $mustValidateSecret = true);
+    public function getClientEntity($clientIdentifier, $grantType = null, $clientSecret = null, $mustValidateSecret = true);
 }
diff --git a/src/RequestTypes/AuthorizationRequest.php b/src/RequestTypes/AuthorizationRequest.php
index 41bfb509..ce5a0034 100644
--- a/src/RequestTypes/AuthorizationRequest.php
+++ b/src/RequestTypes/AuthorizationRequest.php
@@ -53,7 +53,7 @@ class AuthorizationRequest
     /**
      * The redirect URI used in the request
      *
-     * @var string
+     * @var string|null
      */
     protected $redirectUri;
 
@@ -159,7 +159,7 @@ class AuthorizationRequest
     }
 
     /**
-     * @return string
+     * @return string|null
      */
     public function getRedirectUri()
     {
@@ -167,7 +167,7 @@ class AuthorizationRequest
     }
 
     /**
-     * @param string $redirectUri
+     * @param string|null $redirectUri
      */
     public function setRedirectUri($redirectUri)
     {
diff --git a/src/ResourceServer.php b/src/ResourceServer.php
index 5e9c13f3..e1f98d6d 100644
--- a/src/ResourceServer.php
+++ b/src/ResourceServer.php
@@ -63,7 +63,9 @@ class ResourceServer
             $this->authorizationValidator = new BearerTokenValidator($this->accessTokenRepository);
         }
 
-        $this->authorizationValidator->setPublicKey($this->publicKey);
+        if ($this->authorizationValidator instanceof BearerTokenValidator === true) {
+            $this->authorizationValidator->setPublicKey($this->publicKey);
+        }
 
         return $this->authorizationValidator;
     }
diff --git a/tests/AuthorizationServerTest.php b/tests/AuthorizationServerTest.php
index 8b409a00..b003c23f 100644
--- a/tests/AuthorizationServerTest.php
+++ b/tests/AuthorizationServerTest.php
@@ -19,15 +19,14 @@ use LeagueTests\Stubs\ClientEntity;
 use LeagueTests\Stubs\ScopeEntity;
 use LeagueTests\Stubs\StubResponseType;
 use LeagueTests\Stubs\UserEntity;
-use Psr\Http\Message\ResponseInterface;
 use PHPUnit\Framework\TestCase;
+use Psr\Http\Message\ResponseInterface;
 use Zend\Diactoros\Response;
 use Zend\Diactoros\ServerRequest;
 use Zend\Diactoros\ServerRequestFactory;
 
 class AuthorizationServerTest extends TestCase
 {
-
     const DEFAULT_SCOPE = 'basic';
 
     public function setUp()
@@ -198,16 +197,16 @@ class AuthorizationServerTest extends TestCase
         $clientRepositoryMock->method('getClientEntity')->willReturn($client);
 
         $grant = new AuthCodeGrant(
-            $this->getMock(AuthCodeRepositoryInterface::class),
-            $this->getMock(RefreshTokenRepositoryInterface::class),
+            $this->getMockBuilder(AuthCodeRepositoryInterface::class)->getMock(),
+            $this->getMockBuilder(RefreshTokenRepositoryInterface::class)->getMock(),
             new \DateInterval('PT10M')
         );
         $grant->setClientRepository($clientRepositoryMock);
 
         $server = new AuthorizationServer(
             $clientRepositoryMock,
-            $this->getMock(AccessTokenRepositoryInterface::class),
-            $this->getMock(ScopeRepositoryInterface::class),
+            $this->getMockBuilder(AccessTokenRepositoryInterface::class)->getMock(),
+            $this->getMockBuilder(ScopeRepositoryInterface::class)->getMock(),
             'file://' . __DIR__ . '/Stubs/private.key',
             'file://' . __DIR__ . '/Stubs/public.key'
         );
diff --git a/tests/ResponseTypes/BearerResponseTypeTest.php b/tests/ResponseTypes/BearerResponseTypeTest.php
index 56ae9e3e..31245b07 100644
--- a/tests/ResponseTypes/BearerResponseTypeTest.php
+++ b/tests/ResponseTypes/BearerResponseTypeTest.php
@@ -20,9 +20,7 @@ class BearerResponseTypeTest extends TestCase
 {
     public function testGenerateHttpResponse()
     {
-        $accessTokenRepositoryMock = $this->getMockBuilder(AccessTokenRepositoryInterface::class)->getMock();
-
-        $responseType = new BearerTokenResponse($accessTokenRepositoryMock);
+        $responseType = new BearerTokenResponse();
         $responseType->setPrivateKey(new CryptKey('file://' . __DIR__ . '/../Stubs/private.key'));
         $responseType->setEncryptionKey(base64_encode(random_bytes(36)));
 
@@ -64,9 +62,7 @@ class BearerResponseTypeTest extends TestCase
 
     public function testGenerateHttpResponseWithExtraParams()
     {
-        $accessTokenRepositoryMock = $this->getMockBuilder(AccessTokenRepositoryInterface::class)->getMock();
-
-        $responseType = new BearerTokenResponseWithParams($accessTokenRepositoryMock);
+        $responseType = new BearerTokenResponseWithParams();
         $responseType->setPrivateKey(new CryptKey('file://' . __DIR__ . '/../Stubs/private.key'));
         $responseType->setEncryptionKey(base64_encode(random_bytes(36)));
 
@@ -111,10 +107,7 @@ class BearerResponseTypeTest extends TestCase
 
     public function testDetermineAccessTokenInHeaderValidToken()
     {
-        $accessTokenRepositoryMock = $this->getMockBuilder(AccessTokenRepositoryInterface::class)->getMock();
-        $accessTokenRepositoryMock->method('isAccessTokenRevoked')->willReturn(false);
-
-        $responseType = new BearerTokenResponse($accessTokenRepositoryMock);
+        $responseType = new BearerTokenResponse();
         $responseType->setPrivateKey(new CryptKey('file://' . __DIR__ . '/../Stubs/private.key'));
         $responseType->setEncryptionKey(base64_encode(random_bytes(36)));
 
@@ -158,9 +151,8 @@ class BearerResponseTypeTest extends TestCase
     public function testDetermineAccessTokenInHeaderInvalidJWT()
     {
         $accessTokenRepositoryMock = $this->getMockBuilder(AccessTokenRepositoryInterface::class)->getMock();
-        $accessTokenRepositoryMock->method('isAccessTokenRevoked')->willReturn(false);
 
-        $responseType = new BearerTokenResponse($accessTokenRepositoryMock);
+        $responseType = new BearerTokenResponse();
         $responseType->setPrivateKey(new CryptKey('file://' . __DIR__ . '/../Stubs/private.key'));
         $responseType->setEncryptionKey(base64_encode(random_bytes(36)));
 
@@ -247,9 +239,7 @@ class BearerResponseTypeTest extends TestCase
 
     public function testDetermineAccessTokenInHeaderInvalidToken()
     {
-        $accessTokenRepositoryMock = $this->getMockBuilder(AccessTokenRepositoryInterface::class)->getMock();
-
-        $responseType = new BearerTokenResponse($accessTokenRepositoryMock);
+        $responseType = new BearerTokenResponse();
         $responseType->setPrivateKey(new CryptKey('file://' . __DIR__ . '/../Stubs/private.key'));
         $responseType->setEncryptionKey(base64_encode(random_bytes(36)));
 
@@ -273,9 +263,7 @@ class BearerResponseTypeTest extends TestCase
 
     public function testDetermineMissingBearerInHeader()
     {
-        $accessTokenRepositoryMock = $this->getMockBuilder(AccessTokenRepositoryInterface::class)->getMock();
-
-        $responseType = new BearerTokenResponse($accessTokenRepositoryMock);
+        $responseType = new BearerTokenResponse();
         $responseType->setPrivateKey(new CryptKey('file://' . __DIR__ . '/../Stubs/private.key'));
         $responseType->setEncryptionKey(base64_encode(random_bytes(36)));
 
diff --git a/tests/CryptKeyTest.php b/tests/Utils/CryptKeyTest.php
similarity index 82%
rename from tests/CryptKeyTest.php
rename to tests/Utils/CryptKeyTest.php
index 70bbc8d7..9f3f337c 100644
--- a/tests/CryptKeyTest.php
+++ b/tests/Utils/CryptKeyTest.php
@@ -17,7 +17,7 @@ class CryptKeyTest extends TestCase
 
     public function testKeyCreation()
     {
-        $keyFile = __DIR__ . '/Stubs/public.key';
+        $keyFile = __DIR__ . '/../Stubs/public.key';
         $key = new CryptKey($keyFile, 'secret');
 
         $this->assertEquals('file://' . $keyFile, $key->getKeyPath());
@@ -26,7 +26,7 @@ class CryptKeyTest extends TestCase
 
     public function testKeyFileCreation()
     {
-        $keyContent = file_get_contents(__DIR__ . '/Stubs/public.key');
+        $keyContent = file_get_contents(__DIR__ . '/../Stubs/public.key');
         $key = new CryptKey($keyContent);
 
         $this->assertEquals(
@@ -34,7 +34,7 @@ class CryptKeyTest extends TestCase
             $key->getKeyPath()
         );
 
-        $keyContent = file_get_contents(__DIR__ . '/Stubs/private.key.crlf');
+        $keyContent = file_get_contents(__DIR__ . '/../Stubs/private.key.crlf');
         $key = new CryptKey($keyContent);
 
         $this->assertEquals(
diff --git a/tests/CryptTraitTest.php b/tests/Utils/CryptTraitTest.php
similarity index 100%
rename from tests/CryptTraitTest.php
rename to tests/Utils/CryptTraitTest.php