diff --git a/src/Symfony/Component/JsonStreamer/Tests/JsonStreamReaderTest.php b/src/Symfony/Component/JsonStreamer/Tests/JsonStreamReaderTest.php
index bb949333a1d87..65585c1b77c7c 100644
--- a/src/Symfony/Component/JsonStreamer/Tests/JsonStreamReaderTest.php
+++ b/src/Symfony/Component/JsonStreamer/Tests/JsonStreamReaderTest.php
@@ -11,6 +11,8 @@
 
 namespace Symfony\Component\JsonStreamer\Tests;
 
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\Attributes\IgnoreDeprecations;
 use PHPUnit\Framework\TestCase;
 use Psr\Container\ContainerInterface;
 use Symfony\Component\JsonStreamer\JsonStreamReader;
@@ -179,6 +181,8 @@ public function testReadObjectWithDateTimes()
         }, '{"interface":"2024-11-20","immutable":"2025-11-20"}', Type::object(DummyWithDateTimes::class));
     }
 
+    #[IgnoreDeprecations]
+    #[Group('legacy')]
     public function testReadObjectWithSyntheticProperties()
     {
         $reader = new JsonStreamReader($this->createMock(ContainerInterface::class), new SyntheticPropertyMetadataLoader(), $this->streamReadersDir, $this->lazyGhostsDir);
diff --git a/src/Symfony/Component/JsonStreamer/Tests/JsonStreamWriterTest.php b/src/Symfony/Component/JsonStreamer/Tests/JsonStreamWriterTest.php
index e69f9591a5973..473ee25afffea 100644
--- a/src/Symfony/Component/JsonStreamer/Tests/JsonStreamWriterTest.php
+++ b/src/Symfony/Component/JsonStreamer/Tests/JsonStreamWriterTest.php
@@ -12,6 +12,8 @@
 namespace Symfony\Component\JsonStreamer\Tests;
 
 use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\Attributes\IgnoreDeprecations;
 use PHPUnit\Framework\TestCase;
 use Psr\Container\ContainerInterface;
 use Symfony\Component\JsonStreamer\Exception\NotEncodableValueException;
@@ -276,6 +278,8 @@ public function testWriteObjectWithDollarNamedProperties()
         $this->assertWritten('{"$foo":true,"{$foo->bar}":true}', new DummyWithDollarNamedProperties(), Type::object(DummyWithDollarNamedProperties::class));
     }
 
+    #[IgnoreDeprecations]
+    #[Group('legacy')]
     public function testWriteObjectWithSyntheticProperty()
     {
         $writer = new JsonStreamWriter($this->createMock(ContainerInterface::class), new SyntheticPropertyMetadataLoader(), $this->streamWritersDir);
diff --git a/src/Symfony/Component/JsonStreamer/Tests/Read/StreamReaderGeneratorTest.php b/src/Symfony/Component/JsonStreamer/Tests/Read/StreamReaderGeneratorTest.php
index e45323ceca43f..ac9a2acf55b92 100644
--- a/src/Symfony/Component/JsonStreamer/Tests/Read/StreamReaderGeneratorTest.php
+++ b/src/Symfony/Component/JsonStreamer/Tests/Read/StreamReaderGeneratorTest.php
@@ -12,6 +12,8 @@
 namespace Symfony\Component\JsonStreamer\Tests\Read;
 
 use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\Attributes\IgnoreDeprecations;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\JsonStreamer\Exception\UnsupportedException;
 use Symfony\Component\JsonStreamer\Mapping\GenericTypePropertyMetadataLoader;
@@ -54,6 +56,8 @@ protected function setUp(): void
         }
     }
 
+    #[IgnoreDeprecations]
+    #[Group('legacy')]
     #[DataProvider('generatedStreamReaderDataProvider')]
     public function testGeneratedStreamReader(string $fixture, Type $type, ?PropertyMetadataLoaderInterface $propertyMetadataLoader = null)
     {
diff --git a/src/Symfony/Component/JsonStreamer/Tests/Write/StreamWriterGeneratorTest.php b/src/Symfony/Component/JsonStreamer/Tests/Write/StreamWriterGeneratorTest.php
index 8a84c85fce5e2..9f1ba3ec4ee2a 100644
--- a/src/Symfony/Component/JsonStreamer/Tests/Write/StreamWriterGeneratorTest.php
+++ b/src/Symfony/Component/JsonStreamer/Tests/Write/StreamWriterGeneratorTest.php
@@ -12,6 +12,8 @@
 namespace Symfony\Component\JsonStreamer\Tests\Write;
 
 use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\Attributes\IgnoreDeprecations;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\JsonStreamer\Exception\UnsupportedException;
 use Symfony\Component\JsonStreamer\Mapping\GenericTypePropertyMetadataLoader;
@@ -57,6 +59,8 @@ protected function setUp(): void
         }
     }
 
+    #[IgnoreDeprecations]
+    #[Group('legacy')]
     #[DataProvider('generatedStreamWriterDataProvider')]
     public function testGeneratedStreamWriter(string $fixture, Type $type, ?PropertyMetadataLoaderInterface $propertyMetadataLoader = null)
     {