diff --git a/Tests/Authenticator/FormLoginAuthenticatorTest.php b/Tests/Authenticator/FormLoginAuthenticatorTest.php
index 2b7f25f..bab0d70 100644
--- a/Tests/Authenticator/FormLoginAuthenticatorTest.php
+++ b/Tests/Authenticator/FormLoginAuthenticatorTest.php
@@ -36,7 +36,7 @@ public function testAuthenticationFailureWithoutSession()
     {
         $failureResponse = $this->authenticator->onAuthenticationFailure($this->requestWithoutSession, new AuthenticationException());
 
-        $this->assertInstanceOf('Symfony\\Component\\HttpFoundation\\RedirectResponse', $failureResponse);
+        $this->assertInstanceOf(\Symfony\Component\HttpFoundation\RedirectResponse::class, $failureResponse);
         $this->assertEquals(self::LOGIN_URL, $failureResponse->getTargetUrl());
     }
 
@@ -48,7 +48,7 @@ public function testAuthenticationFailureWithSession()
 
         $failureResponse = $this->authenticator->onAuthenticationFailure($this->requestWithSession, new AuthenticationException());
 
-        $this->assertInstanceOf('Symfony\\Component\\HttpFoundation\\RedirectResponse', $failureResponse);
+        $this->assertInstanceOf(\Symfony\Component\HttpFoundation\RedirectResponse::class, $failureResponse);
         $this->assertEquals(self::LOGIN_URL, $failureResponse->getTargetUrl());
     }
 
@@ -63,7 +63,7 @@ public function testStartWithoutSession()
     {
         $failureResponse = $this->authenticator->start($this->requestWithoutSession, new AuthenticationException());
 
-        $this->assertInstanceOf('Symfony\\Component\\HttpFoundation\\RedirectResponse', $failureResponse);
+        $this->assertInstanceOf(\Symfony\Component\HttpFoundation\RedirectResponse::class, $failureResponse);
         $this->assertEquals(self::LOGIN_URL, $failureResponse->getTargetUrl());
     }
 
@@ -71,7 +71,7 @@ public function testStartWithSession()
     {
         $failureResponse = $this->authenticator->start($this->requestWithSession, new AuthenticationException());
 
-        $this->assertInstanceOf('Symfony\\Component\\HttpFoundation\\RedirectResponse', $failureResponse);
+        $this->assertInstanceOf(\Symfony\Component\HttpFoundation\RedirectResponse::class, $failureResponse);
         $this->assertEquals(self::LOGIN_URL, $failureResponse->getTargetUrl());
     }
 
@@ -80,7 +80,7 @@ protected function setUp(): void
         $this->requestWithoutSession = new Request([], [], [], [], [], []);
         $this->requestWithSession = new Request([], [], [], [], [], []);
 
-        $session = $this->getMockBuilder('Symfony\\Component\\HttpFoundation\\Session\\SessionInterface')
+        $session = $this->getMockBuilder(\Symfony\Component\HttpFoundation\Session\SessionInterface::class)
             ->disableOriginalConstructor()
             ->getMock();
         $this->requestWithSession->setSession($session);
diff --git a/Tests/Firewall/GuardAuthenticationListenerTest.php b/Tests/Firewall/GuardAuthenticationListenerTest.php
index c5e1c92..7167ba3 100644
--- a/Tests/Firewall/GuardAuthenticationListenerTest.php
+++ b/Tests/Firewall/GuardAuthenticationListenerTest.php
@@ -234,7 +234,7 @@ public function testSupportsReturnFalseSkipAuth()
 
     public function testReturnNullFromGetCredentials()
     {
-        $this->expectException('UnexpectedValueException');
+        $this->expectException(\UnexpectedValueException::class);
         $authenticator = $this->getMockBuilder(AuthenticatorInterface::class)->getMock();
         $providerKey = 'my_firewall4';
 
@@ -262,17 +262,17 @@ public function testReturnNullFromGetCredentials()
 
     protected function setUp(): void
     {
-        $this->authenticationManager = $this->getMockBuilder('Symfony\Component\Security\Core\Authentication\AuthenticationProviderManager')
+        $this->authenticationManager = $this->getMockBuilder(\Symfony\Component\Security\Core\Authentication\AuthenticationProviderManager::class)
             ->disableOriginalConstructor()
             ->getMock();
 
-        $this->guardAuthenticatorHandler = $this->getMockBuilder('Symfony\Component\Security\Guard\GuardAuthenticatorHandler')
+        $this->guardAuthenticatorHandler = $this->getMockBuilder(\Symfony\Component\Security\Guard\GuardAuthenticatorHandler::class)
             ->disableOriginalConstructor()
             ->getMock();
 
         $this->request = new Request([], [], [], [], [], []);
 
-        $this->event = $this->getMockBuilder('Symfony\Component\HttpKernel\Event\RequestEvent')
+        $this->event = $this->getMockBuilder(\Symfony\Component\HttpKernel\Event\RequestEvent::class)
             ->disableOriginalConstructor()
             ->setMethods(['getRequest'])
             ->getMock();
@@ -281,8 +281,8 @@ protected function setUp(): void
             ->method('getRequest')
             ->willReturn($this->request);
 
-        $this->logger = $this->getMockBuilder('Psr\Log\LoggerInterface')->getMock();
-        $this->rememberMeServices = $this->getMockBuilder('Symfony\Component\Security\Http\RememberMe\RememberMeServicesInterface')->getMock();
+        $this->logger = $this->getMockBuilder(\Psr\Log\LoggerInterface::class)->getMock();
+        $this->rememberMeServices = $this->getMockBuilder(\Symfony\Component\Security\Http\RememberMe\RememberMeServicesInterface::class)->getMock();
     }
 
     protected function tearDown(): void
diff --git a/Tests/GuardAuthenticatorHandlerTest.php b/Tests/GuardAuthenticatorHandlerTest.php
index 5a6c3c2..e115891 100644
--- a/Tests/GuardAuthenticatorHandlerTest.php
+++ b/Tests/GuardAuthenticatorHandlerTest.php
@@ -193,7 +193,7 @@ protected function tearDown(): void
 
     private function configurePreviousSession()
     {
-        $session = $this->getMockBuilder('Symfony\Component\HttpFoundation\Session\SessionInterface')->getMock();
+        $session = $this->getMockBuilder(\Symfony\Component\HttpFoundation\Session\SessionInterface::class)->getMock();
         $session->expects($this->any())
             ->method('getName')
             ->willReturn('test_session_name');
diff --git a/Tests/Provider/GuardAuthenticationProviderTest.php b/Tests/Provider/GuardAuthenticationProviderTest.php
index e00fb12..5ecf12e 100644
--- a/Tests/Provider/GuardAuthenticationProviderTest.php
+++ b/Tests/Provider/GuardAuthenticationProviderTest.php
@@ -125,7 +125,7 @@ public function testCheckCredentialsReturningFalseFailsAuthentication()
      */
     public function testCheckCredentialsReturningNonTrueFailsAuthentication()
     {
-        $this->expectException('Symfony\Component\Security\Core\Exception\BadCredentialsException');
+        $this->expectException(BadCredentialsException::class);
         $providerKey = 'my_uncool_firewall';
 
         $authenticator = $this->getMockBuilder(AuthenticatorInterface::class)->getMock();
@@ -140,7 +140,7 @@ public function testCheckCredentialsReturningNonTrueFailsAuthentication()
             ->method('getCredentials')
             ->willReturn('non-null-value');
 
-        $mockedUser = $this->getMockBuilder('Symfony\Component\Security\Core\User\UserInterface')->getMock();
+        $mockedUser = $this->getMockBuilder(UserInterface::class)->getMock();
         $authenticator->expects($this->once())
             ->method('getUser')
             ->willReturn($mockedUser);
@@ -156,12 +156,12 @@ public function testCheckCredentialsReturningNonTrueFailsAuthentication()
 
     public function testGuardWithNoLongerAuthenticatedTriggersLogout()
     {
-        $this->expectException('Symfony\Component\Security\Core\Exception\AuthenticationExpiredException');
+        $this->expectException(\Symfony\Component\Security\Core\Exception\AuthenticationExpiredException::class);
         $providerKey = 'my_firewall_abc';
 
         // create a token and mark it as NOT authenticated anymore
         // this mimics what would happen if a user "changed" between request
-        $mockedUser = $this->getMockBuilder('Symfony\Component\Security\Core\User\UserInterface')->getMock();
+        $mockedUser = $this->getMockBuilder(UserInterface::class)->getMock();
         $token = new PostAuthenticationGuardToken($mockedUser, $providerKey, ['ROLE_USER']);
         $token->setAuthenticated(false);
 
@@ -175,7 +175,7 @@ public function testSupportsChecksGuardAuthenticatorsTokenOrigin()
         $authenticatorB = $this->getMockBuilder(AuthenticatorInterface::class)->getMock();
         $authenticators = [$authenticatorA, $authenticatorB];
 
-        $mockedUser = $this->getMockBuilder('Symfony\Component\Security\Core\User\UserInterface')->getMock();
+        $mockedUser = $this->getMockBuilder(UserInterface::class)->getMock();
         $provider = new GuardAuthenticationProvider($authenticators, $this->userProvider, 'first_firewall', $this->userChecker);
 
         $token = new PreAuthenticationGuardToken($mockedUser, 'first_firewall_1');
@@ -189,12 +189,12 @@ public function testSupportsChecksGuardAuthenticatorsTokenOrigin()
 
     public function testAuthenticateFailsOnNonOriginatingToken()
     {
-        $this->expectException('Symfony\Component\Security\Core\Exception\AuthenticationException');
+        $this->expectException(\Symfony\Component\Security\Core\Exception\AuthenticationException::class);
         $this->expectExceptionMessageMatches('/second_firewall_0/');
         $authenticatorA = $this->getMockBuilder(AuthenticatorInterface::class)->getMock();
         $authenticators = [$authenticatorA];
 
-        $mockedUser = $this->getMockBuilder('Symfony\Component\Security\Core\User\UserInterface')->getMock();
+        $mockedUser = $this->getMockBuilder(UserInterface::class)->getMock();
         $provider = new GuardAuthenticationProvider($authenticators, $this->userProvider, 'first_firewall', $this->userChecker);
 
         $token = new PreAuthenticationGuardToken($mockedUser, 'second_firewall_0');
@@ -203,9 +203,9 @@ public function testAuthenticateFailsOnNonOriginatingToken()
 
     protected function setUp(): void
     {
-        $this->userProvider = $this->getMockBuilder('Symfony\Component\Security\Core\User\UserProviderInterface')->getMock();
-        $this->userChecker = $this->getMockBuilder('Symfony\Component\Security\Core\User\UserCheckerInterface')->getMock();
-        $this->preAuthenticationToken = $this->getMockBuilder('Symfony\Component\Security\Guard\Token\PreAuthenticationGuardToken')
+        $this->userProvider = $this->getMockBuilder(\Symfony\Component\Security\Core\User\UserProviderInterface::class)->getMock();
+        $this->userChecker = $this->getMockBuilder(\Symfony\Component\Security\Core\User\UserCheckerInterface::class)->getMock();
+        $this->preAuthenticationToken = $this->getMockBuilder(PreAuthenticationGuardToken::class)
             ->disableOriginalConstructor()
             ->getMock();
     }