diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/CacheWarmer/ValidatorCacheWarmerTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/CacheWarmer/ValidatorCacheWarmerTest.php
index 9923b032c048..1fa8883a7833 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/CacheWarmer/ValidatorCacheWarmerTest.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/CacheWarmer/ValidatorCacheWarmerTest.php
@@ -11,7 +11,6 @@
 
 namespace Symfony\Bundle\FrameworkBundle\Tests\CacheWarmer;
 
-use PHPUnit\Framework\Warning;
 use Symfony\Bundle\FrameworkBundle\CacheWarmer\ValidatorCacheWarmer;
 use Symfony\Bundle\FrameworkBundle\Tests\TestCase;
 use Symfony\Component\Cache\Adapter\ArrayAdapter;
@@ -22,12 +21,11 @@
 
 class ValidatorCacheWarmerTest extends TestCase
 {
+    /**
+     * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
+     */
     public function testWarmUp()
     {
-        if (\PHP_VERSION_ID >= 70400) {
-            throw new Warning('PHP 7.4 breaks this test, see https://bugs.php.net/78351.');
-        }
-
         $validatorBuilder = new ValidatorBuilder();
         $validatorBuilder->addXmlMapping(__DIR__.'/../Fixtures/Validation/Resources/person.xml');
         $validatorBuilder->addYamlMapping(__DIR__.'/../Fixtures/Validation/Resources/author.yml');
diff --git a/src/Symfony/Component/Config/Tests/Resource/ClassExistenceResourceTest.php b/src/Symfony/Component/Config/Tests/Resource/ClassExistenceResourceTest.php
index 5b1ec6461f41..44450c32b785 100644
--- a/src/Symfony/Component/Config/Tests/Resource/ClassExistenceResourceTest.php
+++ b/src/Symfony/Component/Config/Tests/Resource/ClassExistenceResourceTest.php
@@ -12,7 +12,6 @@
 namespace Symfony\Component\Config\Tests\Resource;
 
 use PHPUnit\Framework\TestCase;
-use PHPUnit\Framework\Warning;
 use Symfony\Component\Config\Resource\ClassExistenceResource;
 use Symfony\Component\Config\Tests\Fixtures\BadParent;
 use Symfony\Component\Config\Tests\Fixtures\Resource\ConditionalClass;
@@ -76,23 +75,22 @@ public function testExistsKo()
         }
     }
 
+    /**
+     * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
+     */
     public function testBadParentWithTimestamp()
     {
-        if (\PHP_VERSION_ID >= 70400) {
-            throw new Warning('PHP 7.4 breaks this test, see https://bugs.php.net/78351.');
-        }
-
         $res = new ClassExistenceResource(BadParent::class, false);
         $this->assertTrue($res->isFresh(time()));
     }
 
+    /**
+     * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
+     */
     public function testBadParentWithNoTimestamp()
     {
         $this->expectException('ReflectionException');
         $this->expectExceptionMessage('Class Symfony\Component\Config\Tests\Fixtures\MissingParent not found');
-        if (\PHP_VERSION_ID >= 70400) {
-            throw new Warning('PHP 7.4 breaks this test, see https://bugs.php.net/78351.');
-        }
 
         $res = new ClassExistenceResource(BadParent::class, false);
         $res->isFresh(0);
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Compiler/AutowirePassTest.php b/src/Symfony/Component/DependencyInjection/Tests/Compiler/AutowirePassTest.php
index 84d396bebaed..e84968100736 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Compiler/AutowirePassTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Compiler/AutowirePassTest.php
@@ -12,7 +12,6 @@
 namespace Symfony\Component\DependencyInjection\Tests\Compiler;
 
 use PHPUnit\Framework\TestCase;
-use PHPUnit\Framework\Warning;
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\DependencyInjection\Compiler\AutowirePass;
 use Symfony\Component\DependencyInjection\Compiler\AutowireRequiredMethodsPass;
@@ -378,13 +377,13 @@ public function testClassNotFoundThrowsException()
         $pass->process($container);
     }
 
+    /**
+     * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
+     */
     public function testParentClassNotFoundThrowsException()
     {
         $this->expectException('Symfony\Component\DependencyInjection\Exception\AutowiringFailedException');
         $this->expectExceptionMessage('Cannot autowire service "a": argument "$r" of method "Symfony\Component\DependencyInjection\Tests\Compiler\BadParentTypeHintedArgument::__construct()" has type "Symfony\Component\DependencyInjection\Tests\Compiler\OptionalServiceClass" but this class is missing a parent class (Class Symfony\Bug\NotExistClass not found).');
-        if (\PHP_VERSION_ID >= 70400) {
-            throw new Warning('PHP 7.4 breaks this test, see https://bugs.php.net/78351.');
-        }
 
         $container = new ContainerBuilder();
 
@@ -692,12 +691,11 @@ public function getCreateResourceTests()
         ];
     }
 
+    /**
+     * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
+     */
     public function testIgnoreServiceWithClassNotExisting()
     {
-        if (\PHP_VERSION_ID >= 70400) {
-            throw new Warning('PHP 7.4 breaks this test, see https://bugs.php.net/78351.');
-        }
-
         $container = new ContainerBuilder();
 
         $container->register('class_not_exist', __NAMESPACE__.'\OptionalServiceClass');
@@ -894,13 +892,13 @@ public function testExceptionWhenAliasExists()
         $pass->process($container);
     }
 
+    /**
+     * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
+     */
     public function testExceptionWhenAliasDoesNotExist()
     {
         $this->expectException('Symfony\Component\DependencyInjection\Exception\AutowiringFailedException');
         $this->expectExceptionMessage('Cannot autowire service "j": argument "$i" of method "Symfony\Component\DependencyInjection\Tests\Compiler\J::__construct()" references class "Symfony\Component\DependencyInjection\Tests\Compiler\I" but no such service exists. You should maybe alias this class to one of these existing services: "i", "i2".');
-        if (\PHP_VERSION_ID >= 70400) {
-            throw new Warning('PHP 7.4 breaks this test, see https://bugs.php.net/78351.');
-        }
 
         $container = new ContainerBuilder();
 
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Compiler/ResolveBindingsPassTest.php b/src/Symfony/Component/DependencyInjection/Tests/Compiler/ResolveBindingsPassTest.php
index 85d6e02622f4..c91eeadfd99a 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Compiler/ResolveBindingsPassTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Compiler/ResolveBindingsPassTest.php
@@ -12,7 +12,6 @@
 namespace Symfony\Component\DependencyInjection\Tests\Compiler;
 
 use PHPUnit\Framework\TestCase;
-use PHPUnit\Framework\Warning;
 use Symfony\Component\DependencyInjection\Argument\BoundArgument;
 use Symfony\Component\DependencyInjection\Compiler\AutowireRequiredMethodsPass;
 use Symfony\Component\DependencyInjection\Compiler\ResolveBindingsPass;
@@ -62,13 +61,13 @@ public function testUnusedBinding()
         $pass->process($container);
     }
 
+    /**
+     * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
+     */
     public function testMissingParent()
     {
         $this->expectException('Symfony\Component\DependencyInjection\Exception\InvalidArgumentException');
         $this->expectExceptionMessageRegExp('/Unused binding "\$quz" in service [\s\S]+/');
-        if (\PHP_VERSION_ID >= 70400) {
-            throw new Warning('PHP 7.4 breaks this test, see https://bugs.php.net/78351.');
-        }
 
         $container = new ContainerBuilder();
 
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Dumper/PhpDumperTest.php b/src/Symfony/Component/DependencyInjection/Tests/Dumper/PhpDumperTest.php
index 1d3aa33978f4..20f9da9e145f 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Dumper/PhpDumperTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Dumper/PhpDumperTest.php
@@ -12,7 +12,6 @@
 namespace Symfony\Component\DependencyInjection\Tests\Dumper;
 
 use PHPUnit\Framework\TestCase;
-use PHPUnit\Framework\Warning;
 use Psr\Container\ContainerInterface;
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\DependencyInjection\Argument\IteratorArgument;
@@ -894,12 +893,11 @@ public function testInlineSelfRef()
         $this->assertStringEqualsFile(self::$fixturesPath.'/php/services_inline_self_ref.php', $dumper->dump(['class' => 'Symfony_DI_PhpDumper_Test_Inline_Self_Ref']));
     }
 
+    /**
+     * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
+     */
     public function testHotPathOptimizations()
     {
-        if (\PHP_VERSION_ID >= 70400) {
-            throw new Warning('PHP 7.4 breaks this test, see https://bugs.php.net/78351.');
-        }
-
         $container = include self::$fixturesPath.'/containers/container_inline_requires.php';
         $container->setParameter('inline_requires', true);
         $container->compile();
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Loader/FileLoaderTest.php b/src/Symfony/Component/DependencyInjection/Tests/Loader/FileLoaderTest.php
index 7d002ff03093..3a2b5931502b 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Loader/FileLoaderTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Loader/FileLoaderTest.php
@@ -12,7 +12,6 @@
 namespace Symfony\Component\DependencyInjection\Tests\Loader;
 
 use PHPUnit\Framework\TestCase;
-use PHPUnit\Framework\Warning;
 use Psr\Container\ContainerInterface as PsrContainerInterface;
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\Config\Loader\LoaderResolver;
@@ -108,12 +107,11 @@ public function testRegisterClasses()
         );
     }
 
+    /**
+     * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
+     */
     public function testRegisterClassesWithExclude()
     {
-        if (\PHP_VERSION_ID >= 70400) {
-            throw new Warning('PHP 7.4 breaks this test, see https://bugs.php.net/78351.');
-        }
-
         $container = new ContainerBuilder();
         $container->setParameter('other_dir', 'OtherDir');
         $loader = new TestFileLoader($container, new FileLocator(self::$fixturesPath.'/Fixtures'));
@@ -141,12 +139,11 @@ public function testRegisterClassesWithExclude()
         );
     }
 
+    /**
+     * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
+     */
     public function testNestedRegisterClasses()
     {
-        if (\PHP_VERSION_ID >= 70400) {
-            throw new Warning('PHP 7.4 breaks this test, see https://bugs.php.net/78351.');
-        }
-
         $container = new ContainerBuilder();
         $loader = new TestFileLoader($container, new FileLocator(self::$fixturesPath.'/Fixtures'));
 
@@ -173,12 +170,11 @@ public function testNestedRegisterClasses()
         $this->assertFalse($alias->isPrivate());
     }
 
+    /**
+     * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
+     */
     public function testMissingParentClass()
     {
-        if (\PHP_VERSION_ID >= 70400) {
-            throw new Warning('PHP 7.4 breaks this test, see https://bugs.php.net/78351.');
-        }
-
         $container = new ContainerBuilder();
         $container->setParameter('bad_classes_dir', 'BadClasses');
         $loader = new TestFileLoader($container, new FileLocator(self::$fixturesPath.'/Fixtures'));