diff --git a/src/Symfony/Component/Serializer/Serializer.php b/src/Symfony/Component/Serializer/Serializer.phpindex 1e4fb793e8..08f8e960ff 100644--- a/src/Symfony/Component/Serializer/Serializer.php+++ b/src/Symfony/Component/Serializer/Serializer.php@@ -169,7 +169,7 @@ class Serializer implements SerializerInterface, ContextAwareNormalizerInterface                 switch (true) {                     case ($context[AbstractObjectNormalizer::PRESERVE_EMPTY_OBJECTS] ?? false) && \is_object($data):                         if (!$data instanceof \ArrayObject) {-                            trigger_deprecation('symfony/serializer', '5.4', 'The method "%s()" will return an instance of "%s" as of Symfony 6.0 when the object is iteratable, countable and empty.', __METHOD__, \ArrayObject::class);+                            trigger_deprecation('symfony/serializer', '5.4', 'Returning empty object of class "%s" from "%s()" is deprecated unless it extends "ArrayObject".', get_debug_type($data), __METHOD__);                         }                          return $data;diff --git a/src/Symfony/Component/Serializer/Tests/SerializerTest.php b/src/Symfony/Component/Serializer/Tests/SerializerTest.phpindex 2afbd51c22..ab74b06ab0 100644--- a/src/Symfony/Component/Serializer/Tests/SerializerTest.php+++ b/src/Symfony/Component/Serializer/Tests/SerializerTest.php@@ -578,10 +578,7 @@ class SerializerTest extends TestCase         $this->assertSame($expected, $serializer->serialize($data, 'json'));     }-    /**-     * @dataProvider provideObjectOrCollectionTests-     * @group legacy-     */+    /** @dataProvider provideObjectOrCollectionTests */     public function testNormalizePreserveEmptyArrayObject(Serializer $serializer, array $data)     {         $expected = '{"a1":{},"a2":{"k":"v"},"b1":[],"b2":{"k":"v"},"c1":{"nested":{}},"c2":{"nested":{"k":"v"}},"d1":{"nested":[]},"d2":{"nested":{"k":"v"}},"e1":{"map":[]},"e2":{"map":{"k":"v"}},"f1":{"map":{}},"f2":{"map":{"k":"v"}},"g1":{"list":{"list":[]},"settings":[]},"g2":{"list":["greg"],"settings":[]}}';@@ -599,10 +596,7 @@ class SerializerTest extends TestCase         ]));     }-    /**-     * @dataProvider provideObjectOrCollectionTests-     * @group legacy-     */+    /** @dataProvider provideObjectOrCollectionTests */     public function testNormalizeEmptyArrayAsObjectAndPreserveEmptyArrayObject(Serializer $serializer, array $data)     {         $expected = '{"a1":{},"a2":{"k":"v"},"b1":{},"b2":{"k":"v"},"c1":{"nested":{}},"c2":{"nested":{"k":"v"}},"d1":{"nested":{}},"d2":{"nested":{"k":"v"}},"e1":{"map":{}},"e2":{"map":{"k":"v"}},"f1":{"map":{}},"f2":{"map":{"k":"v"}},"g1":{"list":{"list":[]},"settings":{}},"g2":{"list":["greg"],"settings":{}}}';@@ -797,13 +791,15 @@ class Baz     } }-class DummyList implements \Countable, \IteratorAggregate+class DummyList extends \ArrayObject {     public $list;      public function __construct(array $list)     {         $this->list = $list;++        $this->setFlags(\ArrayObject::STD_PROP_LIST);     }      public function count(): int