diff --git a/src/Symfony/Component/VarDumper/Caster/ReflectionCaster.php b/src/Symfony/Component/VarDumper/Caster/ReflectionCaster.php
index 8d5f428e51..95c1dbf6ff 100644
--- a/src/Symfony/Component/VarDumper/Caster/ReflectionCaster.php
+++ b/src/Symfony/Component/VarDumper/Caster/ReflectionCaster.php
@@ -96,11 +96,20 @@ class ReflectionCaster
     {
         $prefix = Caster::PREFIX_VIRTUAL;
 
-        $a += [
-            $prefix.'name' => $c instanceof \ReflectionNamedType ? $c->getName() : (string) $c,
-            $prefix.'allowsNull' => $c->allowsNull(),
-            $prefix.'isBuiltin' => $c->isBuiltin(),
-        ];
+        if ($c instanceof \ReflectionNamedType || \PHP_VERSION_ID < 80000) {
+            $a += [
+                $prefix.'name' => $c instanceof \ReflectionNamedType ? $c->getName() : (string) $c,
+                $prefix.'allowsNull' => $c->allowsNull(),
+                $prefix.'isBuiltin' => $c->isBuiltin(),
+            ];
+        } elseif ($c instanceof \ReflectionUnionType) {
+            $a[$prefix.'allowsNull'] = $c->allowsNull();
+            self::addMap($a, $c, [
+                'types' => 'getTypes',
+            ]);
+        } else {
+            $a[$prefix.'allowsNull'] = $c->allowsNull();
+        }
 
         return $a;
     }
@@ -377,7 +386,7 @@ class ReflectionCaster
         }
     }
 
-    private static function addMap(array &$a, \Reflector $c, array $map, string $prefix = Caster::PREFIX_VIRTUAL)
+    private static function addMap(array &$a, $c, array $map, string $prefix = Caster::PREFIX_VIRTUAL)
     {
         foreach ($map as $k => $m) {
             if (\PHP_VERSION_ID >= 80000 && 'isDisabled' === $k) {
diff --git a/src/Symfony/Component/VarDumper/Tests/Caster/ReflectionCasterTest.php b/src/Symfony/Component/VarDumper/Tests/Caster/ReflectionCasterTest.php
index 9fc8dcaf0d..3f5497573a 100644
--- a/src/Symfony/Component/VarDumper/Tests/Caster/ReflectionCasterTest.php
+++ b/src/Symfony/Component/VarDumper/Tests/Caster/ReflectionCasterTest.php
@@ -14,8 +14,11 @@ namespace Symfony\Component\VarDumper\Tests\Caster;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\VarDumper\Caster\Caster;
 use Symfony\Component\VarDumper\Test\VarDumperTestTrait;
+use Symfony\Component\VarDumper\Tests\Fixtures\ExtendsReflectionTypeFixture;
 use Symfony\Component\VarDumper\Tests\Fixtures\GeneratorDemo;
 use Symfony\Component\VarDumper\Tests\Fixtures\NotLoadableClass;
+use Symfony\Component\VarDumper\Tests\Fixtures\ReflectionNamedTypeFixture;
+use Symfony\Component\VarDumper\Tests\Fixtures\ReflectionUnionTypeFixture;
 
 /**
  * @author Nicolas Grekas <p@tchwork.com>
@@ -75,7 +78,7 @@ Closure($x) {
     $b: & 123
   }
   file: "%sReflectionCasterTest.php"
-  line: "68 to 68"
+  line: "71 to 71"
 }
 EOTXT
             , $var
@@ -211,6 +214,104 @@ EOTXT
         );
     }
 
+    /**
+     * @requires PHP 7.4
+     */
+    public function testReflectionPropertyScalar()
+    {
+        $var = new \ReflectionProperty(ReflectionNamedTypeFixture::class, 'a');
+        $this->assertDumpMatchesFormat(
+            <<<'EOTXT'
+ReflectionProperty {
+  +name: "a"
+  +class: "Symfony\Component\VarDumper\Tests\Fixtures\ReflectionNamedTypeFixture"
+  modifiers: "public"
+}
+EOTXT
+            , $var
+        );
+    }
+
+    /**
+     * @requires PHP 7.4
+     */
+    public function testReflectionNamedType()
+    {
+        $var = (new \ReflectionProperty(ReflectionNamedTypeFixture::class, 'a'))->getType();
+        $this->assertDumpMatchesFormat(
+            <<<'EOTXT'
+ReflectionNamedType {
+  name: "int"
+  allowsNull: false
+  isBuiltin: true
+}
+EOTXT
+            , $var
+        );
+    }
+
+    /**
+     * @requires PHP 8
+     */
+    public function testReflectionUnionType()
+    {
+        $var = (new \ReflectionProperty(ReflectionUnionTypeFixture::class, 'a'))->getType();
+        $this->assertDumpMatchesFormat(
+            <<<'EOTXT'
+ReflectionUnionType {
+  allowsNull: false
+  types: array:2 [
+    0 => ReflectionNamedType {
+      name: "string"
+      allowsNull: false
+      isBuiltin: true
+    }
+    1 => ReflectionNamedType {
+      name: "int"
+      allowsNull: false
+      isBuiltin: true
+    }
+  ]
+}
+EOTXT
+            , $var
+        );
+    }
+
+    /**
+     * @requires PHP 8
+     */
+    public function testExtendsReflectionType()
+    {
+        $var = new ExtendsReflectionTypeFixture();
+        $this->assertDumpMatchesFormat(
+            <<<'EOTXT'
+Symfony\Component\VarDumper\Tests\Fixtures\ExtendsReflectionTypeFixture {
+  allowsNull: false
+}
+EOTXT
+            , $var
+        );
+    }
+
+    /**
+     * @requires PHP < 8
+     */
+    public function testLegacyExtendsReflectionType()
+    {
+        $var = new ExtendsReflectionTypeFixture();
+        $this->assertDumpMatchesFormat(
+            <<<'EOTXT'
+Symfony\Component\VarDumper\Tests\Fixtures\ExtendsReflectionTypeFixture {
+  name: "fake"
+  allowsNull: false
+  isBuiltin: false
+}
+EOTXT
+            , $var
+        );
+    }
+
     public function testReturnType()
     {
         $f = eval('return function ():int {};');
diff --git a/src/Symfony/Component/VarDumper/Tests/Fixtures/ExtendsReflectionTypeFixture.php b/src/Symfony/Component/VarDumper/Tests/Fixtures/ExtendsReflectionTypeFixture.php
new file mode 100644
index 0000000000..1ee3d8c384
--- /dev/null
+++ b/src/Symfony/Component/VarDumper/Tests/Fixtures/ExtendsReflectionTypeFixture.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Symfony\Component\VarDumper\Tests\Fixtures;
+
+class ExtendsReflectionTypeFixture extends \ReflectionType
+{
+    public function allowsNull(): bool
+    {
+        return false;
+    }
+
+    public function isBuiltin(): bool
+    {
+        return false;
+    }
+
+    public function __toString(): string
+    {
+        return 'fake';
+    }
+}
diff --git a/src/Symfony/Component/VarDumper/Tests/Fixtures/ReflectionNamedTypeFixture.php b/src/Symfony/Component/VarDumper/Tests/Fixtures/ReflectionNamedTypeFixture.php
new file mode 100644
index 0000000000..41edf62121
--- /dev/null
+++ b/src/Symfony/Component/VarDumper/Tests/Fixtures/ReflectionNamedTypeFixture.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Symfony\Component\VarDumper\Tests\Fixtures;
+
+class ReflectionNamedTypeFixture
+{
+    public int $a;
+}
diff --git a/src/Symfony/Component/VarDumper/Tests/Fixtures/ReflectionUnionTypeFixture.php b/src/Symfony/Component/VarDumper/Tests/Fixtures/ReflectionUnionTypeFixture.php
new file mode 100644
index 0000000000..2d11e6f4a1
--- /dev/null
+++ b/src/Symfony/Component/VarDumper/Tests/Fixtures/ReflectionUnionTypeFixture.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Symfony\Component\VarDumper\Tests\Fixtures;
+
+class ReflectionUnionTypeFixture
+{
+    public int|string $a;
+}