diff --git a/config/set/php85.php b/config/set/php85.php
index 19715d7a0c2..cee158fa245 100644
--- a/config/set/php85.php
+++ b/config/set/php85.php
@@ -9,6 +9,7 @@
 use Rector\Config\RectorConfig;
 use Rector\Php85\Rector\ArrayDimFetch\ArrayFirstLastRector;
 use Rector\Php85\Rector\ClassMethod\NullDebugInfoReturnRector;
+use Rector\Php85\Rector\Class_\SleepToSerializeRector;
 use Rector\Php85\Rector\Const_\DeprecatedAnnotationToDeprecatedAttributeRector;
 use Rector\Php85\Rector\FuncCall\ArrayKeyExistsNullToEmptyStringRector;
 use Rector\Php85\Rector\FuncCall\ChrArgModuloRector;
@@ -38,6 +39,7 @@
             ColonAfterSwitchCaseRector::class,
             ArrayKeyExistsNullToEmptyStringRector::class,
             ChrArgModuloRector::class,
+            SleepToSerializeRector::class,
             OrdSingleByteRector::class,
         ]
     );
diff --git a/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/Fixture/skip_sleep_empty.php.inc b/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/Fixture/skip_sleep_empty.php.inc
new file mode 100644
index 00000000000..c0aba35565e
--- /dev/null
+++ b/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/Fixture/skip_sleep_empty.php.inc
@@ -0,0 +1,15 @@
+<?php
+declare(strict_types=1);
+
+namespace Rector\Tests\Php85\Rector\Class_\SleepToSerializeRector\Fixture;
+
+class SkipSleepEmpty {
+    private $id;
+    private $name;
+
+    public function __sleep(): array {
+        return [];
+    }
+}
+?>
+?>
diff --git a/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/Fixture/skip_sleep_null.php.inc b/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/Fixture/skip_sleep_null.php.inc
new file mode 100644
index 00000000000..93efd11e174
--- /dev/null
+++ b/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/Fixture/skip_sleep_null.php.inc
@@ -0,0 +1,14 @@
+<?php
+declare(strict_types=1);
+
+namespace Rector\Tests\Php85\Rector\Class_\SleepToSerializeRector\Fixture;
+
+class SkipSleepNull {
+    private $id;
+    private $name;
+
+    public function __sleep() {
+        return null;
+    }
+}
+?>
diff --git a/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/Fixture/sleep.php.inc b/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/Fixture/sleep.php.inc
new file mode 100644
index 00000000000..d41ff9bef18
--- /dev/null
+++ b/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/Fixture/sleep.php.inc
@@ -0,0 +1,29 @@
+<?php
+declare(strict_types=1);
+
+namespace Rector\Tests\Php85\Rector\Class_\SleepToSerializeRector\Fixture;
+
+class User {
+    private $id;
+    private $name;
+
+    public function __sleep() {
+        return ['id', 'name'];
+    }
+}
+?>
+-----
+<?php
+declare(strict_types=1);
+
+namespace Rector\Tests\Php85\Rector\Class_\SleepToSerializeRector\Fixture;
+
+class User {
+    private $id;
+    private $name;
+
+    public function __serialize(): array {
+        return ['id' => $this->id, 'name' => $this->name];
+    }
+}
+?>
diff --git a/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/SleepToSerializeRectorTest.php b/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/SleepToSerializeRectorTest.php
new file mode 100644
index 00000000000..5234b35a750
--- /dev/null
+++ b/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/SleepToSerializeRectorTest.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\Php85\Rector\Class_\SleepToSerializeRector;
+
+use Iterator;
+use PHPUnit\Framework\Attributes\DataProvider;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class SleepToSerializeRectorTest extends AbstractRectorTestCase
+{
+    #[DataProvider('provideData')]
+    public function test(string $filePath): void
+    {
+        $this->doTestFile($filePath);
+    }
+
+    public static function provideData(): Iterator
+    {
+        return self::yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/configured_rule.php';
+    }
+}
diff --git a/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/config/configured_rule.php b/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/config/configured_rule.php
new file mode 100644
index 00000000000..56ac5753670
--- /dev/null
+++ b/rules-tests/Php85/Rector/Class_/SleepToSerializeRector/config/configured_rule.php
@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\Php85\Rector\Class_\SleepToSerializeRector;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->rule(SleepToSerializeRector::class);
+};
diff --git a/rules/Php85/Rector/Class_/SleepToSerializeRector.php b/rules/Php85/Rector/Class_/SleepToSerializeRector.php
new file mode 100644
index 00000000000..a389d570d96
--- /dev/null
+++ b/rules/Php85/Rector/Class_/SleepToSerializeRector.php
@@ -0,0 +1,139 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Php85\Rector\Class_;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\Array_;
+use PhpParser\Node\Expr\ArrayItem;
+use PhpParser\Node\Expr\PropertyFetch;
+use PhpParser\Node\Identifier;
+use PhpParser\Node\Stmt\Class_;
+use PhpParser\Node\Stmt\ClassMethod;
+use Rector\PhpParser\Node\BetterNodeFinder;
+use Rector\Rector\AbstractRector;
+use Rector\TypeDeclaration\NodeAnalyzer\ReturnAnalyzer;
+use Rector\ValueObject\PhpVersionFeature;
+use Rector\VersionBonding\Contract\MinPhpVersionInterface;
+use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
+use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
+
+/**
+ * @see https://3v4l.org/51uu0
+ * @see https://3v4l.org/ktJnk
+ * @see https://wiki.php.net/rfc/deprecations_php_8_5#deprecate_the_sleep_and_wakeup_magic_methods
+ * @see \Rector\Tests\Php85\Rector\Class_\SleepToSerializeRector\SleepToSerializeRectorTest
+ */
+final class SleepToSerializeRector extends AbstractRector implements MinPhpVersionInterface
+{
+    public function __construct(
+        private BetterNodeFinder $betterNodeFinder,
+        private ReturnAnalyzer $returnAnalyzer
+    ) {
+    }
+
+    public function provideMinPhpVersion(): int
+    {
+        return PhpVersionFeature::DEPRECATED_METHOD_SLEEP;
+    }
+
+    public function getRuleDefinition(): RuleDefinition
+    {
+        return new RuleDefinition(
+            'Change __sleep() to __serialize() with correct return values',
+            [
+                new CodeSample(
+                    <<<'CODE_SAMPLE'
+class User {
+    private $id;
+    private $name;
+
+    public function __sleep() {
+        return ['id', 'name'];
+    }
+}
+CODE_SAMPLE
+                    ,
+                    <<<'CODE_SAMPLE'
+class User {
+    private $id;
+    private $name;
+
+    public function __serialize(): array {
+        return [
+            'id' => $this->id,
+            'name' => $this->name,
+        ];
+    }
+}
+CODE_SAMPLE
+                ),
+            ]
+        );
+    }
+
+    /**
+     * @return array<class-string<Node>>
+     */
+    public function getNodeTypes(): array
+    {
+        return [Class_::class];
+    }
+
+    /**
+     * @param Class_ $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        if ($node->getMethod('__serialize') instanceof ClassMethod) {
+            return null;
+        }
+
+        $classMethod = $node->getMethod('__sleep');
+        if (! $classMethod instanceof ClassMethod) {
+            return null;
+        }
+
+        if ($classMethod->returnType instanceof Identifier && $this->isName($classMethod->returnType, 'array')) {
+            return null;
+        }
+
+        $returns = $this->betterNodeFinder->findReturnsScoped($classMethod);
+        if (! $this->returnAnalyzer->hasOnlyReturnWithExpr($classMethod, $returns)) {
+            return null;
+        }
+
+        $hasChanged = false;
+        foreach ($returns as $return) {
+            if (! $return->expr instanceof Array_) {
+                return null;
+            }
+
+            if (count($return->expr->items) > 0) {
+                $newItems = [];
+                foreach ($return->expr->items as $item) {
+                    if ($item !== null && $item->value instanceof Node\Scalar\String_) {
+                        $propName = $item->value->value;
+                        $newItems[] = new ArrayItem(
+                            new PropertyFetch(new Node\Expr\Variable('this'), $propName),
+                            $item->value
+                        );
+                    }
+                }
+                if (count($newItems) > 0) {
+                    $hasChanged = true;
+                    $return->expr->items = $newItems;
+                }
+            }
+        }
+
+        if ($hasChanged) {
+            $classMethod->name = new Identifier('__serialize');
+            $classMethod->returnType = new Identifier('array');
+            return $node;
+        }
+
+        return null;
+    }
+}
diff --git a/src/ValueObject/PhpVersionFeature.php b/src/ValueObject/PhpVersionFeature.php
index 9747fdb8345..78a946ee218 100644
--- a/src/ValueObject/PhpVersionFeature.php
+++ b/src/ValueObject/PhpVersionFeature.php
@@ -811,6 +811,12 @@ final class PhpVersionFeature
      */
     public const DEPRECATE_OUTSIDE_INTERVEL_VAL_IN_CHR_FUNCTION = PhpVersion::PHP_85;
 
+    /**
+     * @see https://wiki.php.net/rfc/deprecations_php_8_5#deprecate_the_sleep_and_wakeup_magic_methods
+     * @var int
+     */
+    public const DEPRECATED_METHOD_SLEEP = PhpVersion::PHP_85;
+  
     /**
      * @see https://wiki.php.net/rfc/deprecations_php_8_5#deprecate_passing_string_which_are_not_one_byte_long_to_ord
      * @var int