diff --git a/src/Symfony/Component/BrowserKit/Tests/Test/Constraint/BrowserCookieValueSameTest.php b/src/Symfony/Component/BrowserKit/Tests/Test/Constraint/BrowserCookieValueSameTest.php
index caccd640b7..f2de26f9df 100644
--- a/src/Symfony/Component/BrowserKit/Tests/Test/Constraint/BrowserCookieValueSameTest.php
+++ b/src/Symfony/Component/BrowserKit/Tests/Test/Constraint/BrowserCookieValueSameTest.php
@@ -21,7 +21,7 @@ use Symfony\Component\BrowserKit\Test\Constraint\BrowserCookieValueSame;
 
 class BrowserCookieValueSameTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $browser = $this->getBrowser();
         $constraint = new BrowserCookieValueSame('foo', 'bar', false, '/path');
diff --git a/src/Symfony/Component/BrowserKit/Tests/Test/Constraint/BrowserHasCookieTest.php b/src/Symfony/Component/BrowserKit/Tests/Test/Constraint/BrowserHasCookieTest.php
index 87180efd3b..f6cb6d50c9 100644
--- a/src/Symfony/Component/BrowserKit/Tests/Test/Constraint/BrowserHasCookieTest.php
+++ b/src/Symfony/Component/BrowserKit/Tests/Test/Constraint/BrowserHasCookieTest.php
@@ -21,7 +21,7 @@ use Symfony\Component\BrowserKit\Test\Constraint\BrowserHasCookie;
 
 class BrowserHasCookieTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $browser = $this->getBrowser();
         $constraint = new BrowserHasCookie('foo', '/path');
@@ -42,7 +42,7 @@ class BrowserHasCookieTest extends TestCase
         $this->fail();
     }
 
-    public function testConstraintWithWrongPath(): void
+    public function testConstraintWithWrongPath()
     {
         $browser = $this->getBrowser();
         $constraint = new BrowserHasCookie('foo', '/other');
@@ -57,7 +57,7 @@ class BrowserHasCookieTest extends TestCase
         $this->fail();
     }
 
-    public function testConstraintWithWrongDomain(): void
+    public function testConstraintWithWrongDomain()
     {
         $browser = $this->getBrowser();
         $constraint = new BrowserHasCookie('foo', '/path', 'example.org');
diff --git a/src/Symfony/Component/Console/Tests/Helper/TableTest.php b/src/Symfony/Component/Console/Tests/Helper/TableTest.php
index 3616333eca..dffaaf902c 100644
--- a/src/Symfony/Component/Console/Tests/Helper/TableTest.php
+++ b/src/Symfony/Component/Console/Tests/Helper/TableTest.php
@@ -1263,7 +1263,7 @@ EOTXT;
         return str_replace(\PHP_EOL, "\n", stream_get_contents($output->getStream()));
     }
 
-    public function testWithColspanAndMaxWith(): void
+    public function testWithColspanAndMaxWith()
     {
         $table = new Table($output = $this->getOutputStream());
 
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Compiler/ValidateEnvPlaceholdersPassTest.php b/src/Symfony/Component/DependencyInjection/Tests/Compiler/ValidateEnvPlaceholdersPassTest.php
index c897de47ae..5c3f049234 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Compiler/ValidateEnvPlaceholdersPassTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Compiler/ValidateEnvPlaceholdersPassTest.php
@@ -202,7 +202,7 @@ class ValidateEnvPlaceholdersPassTest extends TestCase
         $this->assertSame($expected, $container->resolveEnvPlaceholders($ext->getConfig()));
     }
 
-    public function testEmptyEnvWhichCannotBeEmptyForScalarNode(): void
+    public function testEmptyEnvWhichCannotBeEmptyForScalarNode()
     {
         $container = new ContainerBuilder();
         $container->registerExtension($ext = new EnvExtension());
@@ -215,7 +215,7 @@ class ValidateEnvPlaceholdersPassTest extends TestCase
         $this->assertSame($expected, $container->resolveEnvPlaceholders($ext->getConfig()));
     }
 
-    public function testEmptyEnvWhichCannotBeEmptyForScalarNodeWithValidation(): void
+    public function testEmptyEnvWhichCannotBeEmptyForScalarNodeWithValidation()
     {
         $this->expectException('Symfony\Component\Config\Definition\Exception\InvalidConfigurationException');
         $this->expectExceptionMessage('The path "env_extension.scalar_node_not_empty_validated" cannot contain an environment variable when empty values are not allowed by definition and are validated.');
@@ -229,7 +229,7 @@ class ValidateEnvPlaceholdersPassTest extends TestCase
         $this->doProcess($container);
     }
 
-    public function testPartialEnvWhichCannotBeEmptyForScalarNode(): void
+    public function testPartialEnvWhichCannotBeEmptyForScalarNode()
     {
         $container = new ContainerBuilder();
         $container->registerExtension($ext = new EnvExtension());
@@ -242,7 +242,7 @@ class ValidateEnvPlaceholdersPassTest extends TestCase
         $this->assertSame($expected, $container->resolveEnvPlaceholders($ext->getConfig()));
     }
 
-    public function testEnvWithVariableNode(): void
+    public function testEnvWithVariableNode()
     {
         $container = new ContainerBuilder();
         $container->registerExtension($ext = new EnvExtension());
@@ -266,7 +266,7 @@ class ValidateEnvPlaceholdersPassTest extends TestCase
         $this->addToAssertionCount(1);
     }
 
-    public function testDiscardedEnvInConfig(): void
+    public function testDiscardedEnvInConfig()
     {
         $container = new ContainerBuilder();
         $container->setParameter('env(BOOLISH)', '1');
diff --git a/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorAttributeValueSameTest.php b/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorAttributeValueSameTest.php
index 9a3716d64f..ab528ab356 100644
--- a/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorAttributeValueSameTest.php
+++ b/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorAttributeValueSameTest.php
@@ -19,7 +19,7 @@ use Symfony\Component\DomCrawler\Test\Constraint\CrawlerSelectorAttributeValueSa
 
 class CrawlerSelectorAttributeValueSameTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $constraint = new CrawlerSelectorAttributeValueSame('input[name="username"]', 'value', 'Fabien');
         $this->assertTrue($constraint->evaluate(new Crawler('<html><body><form><input type="text" name="username" value="Fabien">'), '', true));
diff --git a/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorExistsTest.php b/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorExistsTest.php
index f80bd66706..cf5b2a551c 100644
--- a/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorExistsTest.php
+++ b/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorExistsTest.php
@@ -19,7 +19,7 @@ use Symfony\Component\DomCrawler\Test\Constraint\CrawlerSelectorExists;
 
 class CrawlerSelectorExistsTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $constraint = new CrawlerSelectorExists('title');
         $this->assertTrue($constraint->evaluate(new Crawler('<html><head><title>'), '', true));
diff --git a/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorTextContainsTest.php b/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorTextContainsTest.php
index d61647c388..b92a13187b 100644
--- a/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorTextContainsTest.php
+++ b/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorTextContainsTest.php
@@ -19,7 +19,7 @@ use Symfony\Component\DomCrawler\Test\Constraint\CrawlerSelectorTextContains;
 
 class CrawlerSelectorTextContainsTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $constraint = new CrawlerSelectorTextContains('title', 'Foo');
         $this->assertTrue($constraint->evaluate(new Crawler('<html><head><title>Foobar'), '', true));
diff --git a/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorTextSameTest.php b/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorTextSameTest.php
index f394abbc26..aa0d9a9438 100644
--- a/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorTextSameTest.php
+++ b/src/Symfony/Component/DomCrawler/Tests/Test/Constraint/CrawlerSelectorTextSameTest.php
@@ -19,7 +19,7 @@ use Symfony\Component\DomCrawler\Test\Constraint\CrawlerSelectorTextSame;
 
 class CrawlerSelectorTextSameTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $constraint = new CrawlerSelectorTextSame('title', 'Foo');
         $this->assertTrue($constraint->evaluate(new Crawler('<html><head><title>Foo'), '', true));
diff --git a/src/Symfony/Component/EventDispatcher/Tests/DependencyInjection/RegisterListenersPassTest.php b/src/Symfony/Component/EventDispatcher/Tests/DependencyInjection/RegisterListenersPassTest.php
index f557f1f8a6..a0b94dbc44 100644
--- a/src/Symfony/Component/EventDispatcher/Tests/DependencyInjection/RegisterListenersPassTest.php
+++ b/src/Symfony/Component/EventDispatcher/Tests/DependencyInjection/RegisterListenersPassTest.php
@@ -61,7 +61,7 @@ class RegisterListenersPassTest extends TestCase
         $this->assertEquals($expectedCalls, $eventDispatcherDefinition->getMethodCalls());
     }
 
-    public function testAliasedEventSubscriber(): void
+    public function testAliasedEventSubscriber()
     {
         $builder = new ContainerBuilder();
         $builder->setParameter('event_dispatcher.event_aliases', [AliasedEvent::class => 'aliased_event']);
@@ -231,7 +231,7 @@ class RegisterListenersPassTest extends TestCase
         $this->assertEquals($expectedCalls, $definition->getMethodCalls());
     }
 
-    public function testAliasedEventListener(): void
+    public function testAliasedEventListener()
     {
         $container = new ContainerBuilder();
         $eventAliases = [AliasedEvent::class => 'aliased_event'];
@@ -272,7 +272,7 @@ class RegisterListenersPassTest extends TestCase
         $this->assertEquals($expectedCalls, $definition->getMethodCalls());
     }
 
-    public function testOmitEventNameOnTypedListener(): void
+    public function testOmitEventNameOnTypedListener()
     {
         $container = new ContainerBuilder();
         $container->setParameter('event_dispatcher.event_aliases', [AliasedEvent::class => 'aliased_event']);
@@ -305,7 +305,7 @@ class RegisterListenersPassTest extends TestCase
         $this->assertEquals($expectedCalls, $definition->getMethodCalls());
     }
 
-    public function testOmitEventNameOnUntypedListener(): void
+    public function testOmitEventNameOnUntypedListener()
     {
         $container = new ContainerBuilder();
         $container->register('foo', InvokableListenerService::class)->addTag('kernel.event_listener', ['method' => 'onEvent']);
@@ -318,7 +318,7 @@ class RegisterListenersPassTest extends TestCase
         $registerListenersPass->process($container);
     }
 
-    public function testOmitEventNameAndMethodOnUntypedListener(): void
+    public function testOmitEventNameAndMethodOnUntypedListener()
     {
         $container = new ContainerBuilder();
         $container->register('foo', InvokableListenerService::class)->addTag('kernel.event_listener');
@@ -334,7 +334,7 @@ class RegisterListenersPassTest extends TestCase
     /**
      * @requires PHP 7.2
      */
-    public function testOmitEventNameAndMethodOnGenericListener(): void
+    public function testOmitEventNameAndMethodOnGenericListener()
     {
         $container = new ContainerBuilder();
         $container->register('foo', GenericListener::class)->addTag('kernel.event_listener');
@@ -347,7 +347,7 @@ class RegisterListenersPassTest extends TestCase
         $registerListenersPass->process($container);
     }
 
-    public function testOmitEventNameOnSubscriber(): void
+    public function testOmitEventNameOnSubscriber()
     {
         $container = new ContainerBuilder();
         $container->register('subscriber', IncompleteSubscriber::class)
diff --git a/src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTimeTypeTest.php b/src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTimeTypeTest.php
index d9464265fb..a924df59ed 100644
--- a/src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTimeTypeTest.php
+++ b/src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTimeTypeTest.php
@@ -717,7 +717,7 @@ class DateTimeTypeTest extends BaseTypeTest
         ];
     }
 
-    public function testSubmitStringWithCustomInputFormat(): void
+    public function testSubmitStringWithCustomInputFormat()
     {
         $form = $this->factory->create(static::TESTED_TYPE, null, [
             'model_timezone' => 'UTC',
diff --git a/src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTypeTest.php b/src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTypeTest.php
index 054b46780d..38423e0459 100644
--- a/src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTypeTest.php
+++ b/src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTypeTest.php
@@ -1048,7 +1048,7 @@ class DateTypeTest extends BaseTypeTest
         ];
     }
 
-    public function testSubmitStringWithCustomInputFormat(): void
+    public function testSubmitStringWithCustomInputFormat()
     {
         $form = $this->factory->create(static::TESTED_TYPE, null, [
             'model_timezone' => 'UTC',
diff --git a/src/Symfony/Component/Form/Tests/Extension/Core/Type/NumberTypeTest.php b/src/Symfony/Component/Form/Tests/Extension/Core/Type/NumberTypeTest.php
index 499e942b86..af9354b7be 100644
--- a/src/Symfony/Component/Form/Tests/Extension/Core/Type/NumberTypeTest.php
+++ b/src/Symfony/Component/Form/Tests/Extension/Core/Type/NumberTypeTest.php
@@ -99,7 +99,7 @@ class NumberTypeTest extends BaseTypeTest
         ]);
     }
 
-    public function testDefaultFormattingWithRounding(): void
+    public function testDefaultFormattingWithRounding()
     {
         $form = $this->factory->create(static::TESTED_TYPE, null, ['scale' => 0, 'rounding_mode' => \NumberFormatter::ROUND_UP]);
         $form->setData('12345.54321');
@@ -139,7 +139,7 @@ class NumberTypeTest extends BaseTypeTest
         $this->assertNull($form->getData());
     }
 
-    public function testSubmitNumericInput(): void
+    public function testSubmitNumericInput()
     {
         $form = $this->factory->create(static::TESTED_TYPE, null, ['input' => 'number']);
         $form->submit('1,234');
@@ -149,7 +149,7 @@ class NumberTypeTest extends BaseTypeTest
         $this->assertSame('1,234', $form->getViewData());
     }
 
-    public function testSubmitNumericInputWithScale(): void
+    public function testSubmitNumericInputWithScale()
     {
         $form = $this->factory->create(static::TESTED_TYPE, null, ['input' => 'number', 'scale' => 2]);
         $form->submit('1,234');
@@ -159,7 +159,7 @@ class NumberTypeTest extends BaseTypeTest
         $this->assertSame('1,23', $form->getViewData());
     }
 
-    public function testSubmitStringInput(): void
+    public function testSubmitStringInput()
     {
         $form = $this->factory->create(static::TESTED_TYPE, null, ['input' => 'string']);
         $form->submit('1,234');
@@ -169,7 +169,7 @@ class NumberTypeTest extends BaseTypeTest
         $this->assertSame('1,234', $form->getViewData());
     }
 
-    public function testSubmitStringInputWithScale(): void
+    public function testSubmitStringInputWithScale()
     {
         $form = $this->factory->create(static::TESTED_TYPE, null, ['input' => 'string', 'scale' => 2]);
         $form->submit('1,234');
diff --git a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/RequestAttributeValueSameTest.php b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/RequestAttributeValueSameTest.php
index eca8aed263..c7ee239f3c 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/RequestAttributeValueSameTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/RequestAttributeValueSameTest.php
@@ -19,7 +19,7 @@ use Symfony\Component\HttpFoundation\Test\Constraint\RequestAttributeValueSame;
 
 class RequestAttributeValueSameTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $request = new Request();
         $request->attributes->set('foo', 'bar');
diff --git a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseCookieValueSameTest.php b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseCookieValueSameTest.php
index 778879c328..fc195309a4 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseCookieValueSameTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseCookieValueSameTest.php
@@ -20,7 +20,7 @@ use Symfony\Component\HttpFoundation\Test\Constraint\ResponseCookieValueSame;
 
 class ResponseCookieValueSameTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $response = new Response();
         $response->headers->setCookie(Cookie::create('foo', 'bar', 0, '/path'));
diff --git a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseHasCookieTest.php b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseHasCookieTest.php
index 05ca95fb46..ba1d7f38a3 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseHasCookieTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseHasCookieTest.php
@@ -20,7 +20,7 @@ use Symfony\Component\HttpFoundation\Test\Constraint\ResponseHasCookie;
 
 class ResponseHasCookieTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $response = new Response();
         $response->headers->setCookie(Cookie::create('foo', 'bar'));
diff --git a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseHasHeaderTest.php b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseHasHeaderTest.php
index 7b811a64a2..9a8fc25608 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseHasHeaderTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseHasHeaderTest.php
@@ -19,7 +19,7 @@ use Symfony\Component\HttpFoundation\Test\Constraint\ResponseHasHeader;
 
 class ResponseHasHeaderTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $constraint = new ResponseHasHeader('Date');
         $this->assertTrue($constraint->evaluate(new Response(), '', true));
diff --git a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseHeaderSameTest.php b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseHeaderSameTest.php
index d527f35de8..17a3f2a99b 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseHeaderSameTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseHeaderSameTest.php
@@ -19,7 +19,7 @@ use Symfony\Component\HttpFoundation\Test\Constraint\ResponseHeaderSame;
 
 class ResponseHeaderSameTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $constraint = new ResponseHeaderSame('Cache-Control', 'no-cache, private');
         $this->assertTrue($constraint->evaluate(new Response(), '', true));
diff --git a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseIsRedirectedTest.php b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseIsRedirectedTest.php
index a8314c2599..60590346e2 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseIsRedirectedTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseIsRedirectedTest.php
@@ -19,7 +19,7 @@ use Symfony\Component\HttpFoundation\Test\Constraint\ResponseIsRedirected;
 
 class ResponseIsRedirectedTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $constraint = new ResponseIsRedirected();
 
diff --git a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseIsSuccessfulTest.php b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseIsSuccessfulTest.php
index b59daf8a38..89c3045f16 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseIsSuccessfulTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseIsSuccessfulTest.php
@@ -19,7 +19,7 @@ use Symfony\Component\HttpFoundation\Test\Constraint\ResponseIsSuccessful;
 
 class ResponseIsSuccessfulTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $constraint = new ResponseIsSuccessful();
 
diff --git a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseStatusCodeSameTest.php b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseStatusCodeSameTest.php
index 53200fdd03..80a4eebfc8 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseStatusCodeSameTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/Test/Constraint/ResponseStatusCodeSameTest.php
@@ -19,7 +19,7 @@ use Symfony\Component\HttpFoundation\Test\Constraint\ResponseStatusCodeSame;
 
 class ResponseStatusCodeSameTest extends TestCase
 {
-    public function testConstraint(): void
+    public function testConstraint()
     {
         $constraint = new ResponseStatusCodeSame(200);
         $this->assertTrue($constraint->evaluate(new Response(), '', true));
diff --git a/src/Symfony/Component/Mailer/Tests/Transport/Smtp/SmtpTransportTest.php b/src/Symfony/Component/Mailer/Tests/Transport/Smtp/SmtpTransportTest.php
index 2c8d91e9e4..38229ce844 100644
--- a/src/Symfony/Component/Mailer/Tests/Transport/Smtp/SmtpTransportTest.php
+++ b/src/Symfony/Component/Mailer/Tests/Transport/Smtp/SmtpTransportTest.php
@@ -31,7 +31,7 @@ class SmtpTransportTest extends TestCase
         $this->assertEquals('smtp://127.0.0.1:2525', (string) $t);
     }
 
-    public function testSendDoesNotPingBelowThreshold(): void
+    public function testSendDoesNotPingBelowThreshold()
     {
         $stream = new DummyStream();
         $envelope = new Envelope(new Address('sender@example.org'), [new Address('recipient@example.org')]);
@@ -44,7 +44,7 @@ class SmtpTransportTest extends TestCase
         $this->assertNotContains("NOOP\r\n", $stream->getCommands());
     }
 
-    public function testSendPingAfterTransportException(): void
+    public function testSendPingAfterTransportException()
     {
         $stream = new DummyStream();
         $envelope = new Envelope(new Address('sender@example.org'), [new Address('recipient@example.org')]);
@@ -67,7 +67,7 @@ class SmtpTransportTest extends TestCase
         $this->assertFalse($stream->isClosed());
     }
 
-    public function testSendDoesPingAboveThreshold(): void
+    public function testSendDoesPingAboveThreshold()
     {
         $stream = new DummyStream();
         $envelope = new Envelope(new Address('sender@example.org'), [new Address('recipient@example.org')]);
diff --git a/src/Symfony/Component/Serializer/Tests/Extractor/ObjectPropertyListExtractorTest.php b/src/Symfony/Component/Serializer/Tests/Extractor/ObjectPropertyListExtractorTest.php
index 9701628e90..65e776684f 100644
--- a/src/Symfony/Component/Serializer/Tests/Extractor/ObjectPropertyListExtractorTest.php
+++ b/src/Symfony/Component/Serializer/Tests/Extractor/ObjectPropertyListExtractorTest.php
@@ -17,7 +17,7 @@ use Symfony\Component\Serializer\Extractor\ObjectPropertyListExtractor;
 
 class ObjectPropertyListExtractorTest extends TestCase
 {
-    public function testGetPropertiesWithoutObjectClassResolver(): void
+    public function testGetPropertiesWithoutObjectClassResolver()
     {
         $object = new \stdClass();
         $context = ['bar' => true];
@@ -35,7 +35,7 @@ class ObjectPropertyListExtractorTest extends TestCase
         );
     }
 
-    public function testGetPropertiesWithObjectClassResolver(): void
+    public function testGetPropertiesWithObjectClassResolver()
     {
         $object = new \stdClass();
         $classResolver = function ($objectArg) use ($object): string {