symfony
diff --git a/‎src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php
Lines changed: 4 additions & 0 deletions b/‎src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php
Lines changed: 4 additions & 0 deletions
diff --git a/‎src/Symfony/Component/Serializer/Tests/Normalizer/ObjectNormalizerTest.php
Lines changed: 20 additions & 0 deletions b/‎src/Symfony/Component/Serializer/Tests/Normalizer/ObjectNormalizerTest.php
Lines changed: 20 additions & 0 deletions
diff --git a/‎src/Symfony/Component/Serializer/Tests/Php80Dummy.php
Lines changed: 19 additions & 0 deletions b/‎src/Symfony/Component/Serializer/Tests/Php80Dummy.php
Lines changed: 19 additions & 0 deletions
@@ -537,6 +537,10 @@ private function validateAndDenormalize(string $currentClass, string $attribute,
                 return (float) $data;
             }
 
+            if (Type::BUILTIN_TYPE_FALSE === $builtinType && false === $data) {
+                return $data;
+            }
+
             if (('is_'.$builtinType)($data)) {
                 return $data;
             }
 
@@ -50,6 +50,7 @@
 use Symfony\Component\Serializer\Tests\Normalizer\Features\ObjectToPopulateTestTrait;
 use Symfony\Component\Serializer\Tests\Normalizer\Features\SkipNullValuesTestTrait;
 use Symfony\Component\Serializer\Tests\Normalizer\Features\TypeEnforcementTestTrait;
+use Symfony\Component\Serializer\Tests\Php80Dummy;
 
 /**
  * @author Kévin Dunglas <dunglas@gmail.com>
@@ -699,6 +700,25 @@ public function testExtractAttributesRespectsContext()
         $this->assertSame(['foo' => 'bar', 'bar' => 'foo'], $normalizer->normalize($data, null, ['include_foo_and_bar' => true]));
     }
 
+    /**
+     * @requires PHP 8
+     */
+    public function testDenormalizeFalsePseudoType()
+    {
+        // given a serializer that extracts the attribute types of an object via ReflectionExtractor
+        $propertyTypeExtractor = new PropertyInfoExtractor([], [new ReflectionExtractor()], [], [], []);
+        $objectNormalizer = new ObjectNormalizer(null, null, null, $propertyTypeExtractor);
+
+        $serializer = new Serializer([$objectNormalizer]);
+
+        // when denormalizing some data into an object where an attribute uses the false pseudo type
+        /** @var Php80Dummy $object */
+        $object = $serializer->denormalize(['canBeFalseOrString' => false], Php80Dummy::class);
+
+        // then the attribute that declared false was filled correctly
+        $this->assertFalse($object->canBeFalseOrString);
+    }
+
     public function testAdvancedNameConverter()
     {
         $nameConverter = new class() implements AdvancedNameConverterInterface {
 
@@ -0,0 +1,19 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Symfony\Component\Serializer\Tests;
+
+final class Php80Dummy
+{
+    public false|string $canBeFalseOrString;
+}
Original file line number	Diff line number	Diff line change
`@@ -537,6 +537,10 @@ private function validateAndDenormalize(string $currentClass, string $attribute,`
`537`	`537`	`return (float) $data;`
`538`	`538`	`}`
`539`	`539`
	`540`	`+ if (Type::BUILTIN_TYPE_FALSE === $builtinType && false === $data) {`
	`541`	`+ return $data;`
	`542`	`+ }`
	`543`	`+`
`540`	`544`	`if (('is_'.$builtinType)($data)) {`
`541`	`545`	`return $data;`
`542`	`546`	`}`