diff --git a/packages/VendorLocker/ParentClassMethodTypeOverrideGuard.php b/packages/VendorLocker/ParentClassMethodTypeOverrideGuard.php
index de6ee4ea628..0a39cffb069 100644
--- a/packages/VendorLocker/ParentClassMethodTypeOverrideGuard.php
+++ b/packages/VendorLocker/ParentClassMethodTypeOverrideGuard.php
@@ -15,6 +15,8 @@
 use Rector\Core\Reflection\ReflectionResolver;
 use Rector\Core\ValueObject\MethodName;
 use Rector\NodeNameResolver\NodeNameResolver;
+use Rector\NodeTypeResolver\TypeComparator\TypeComparator;
+use Rector\StaticTypeMapper\StaticTypeMapper;
 use Rector\TypeDeclaration\TypeInferer\ParamTypeInferer;
 use Symplify\SmartFileSystem\Normalizer\PathNormalizer;
 
@@ -25,7 +27,9 @@ public function __construct(
         private readonly PathNormalizer $pathNormalizer,
         private readonly AstResolver $astResolver,
         private readonly ParamTypeInferer $paramTypeInferer,
-        private readonly ReflectionResolver $reflectionResolver
+        private readonly ReflectionResolver $reflectionResolver,
+        private readonly TypeComparator $typeComparator,
+        private readonly StaticTypeMapper $staticTypeMapper
     ) {
     }
 
@@ -138,4 +142,19 @@ public function getParentClassMethod(ClassMethod $classMethod): ?MethodReflectio
 
         return null;
     }
+
+    public function shouldSkipReturnTypeChange(ClassMethod $classMethod, Type $parentType): bool
+    {
+        if ($classMethod->returnType === null) {
+            return false;
+        }
+
+        $currentReturnType = $this->staticTypeMapper->mapPhpParserNodePHPStanType($classMethod->returnType);
+
+        if ($this->typeComparator->isSubtype($currentReturnType, $parentType)) {
+            return true;
+        }
+
+        return $this->typeComparator->areTypesEqual($currentReturnType, $parentType);
+    }
 }
diff --git a/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/AddReturnTypeDeclarationBasedOnParentClassMethodRectorTest.php b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/AddReturnTypeDeclarationBasedOnParentClassMethodRectorTest.php
new file mode 100644
index 00000000000..d361a8de63a
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/AddReturnTypeDeclarationBasedOnParentClassMethodRectorTest.php
@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\TypeDeclaration\Rector\ClassMethod\AddReturnTypeDeclarationBasedOnParentClassMethodRector;
+
+use Iterator;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+use Symplify\SmartFileSystem\SmartFileInfo;
+
+final class AddReturnTypeDeclarationBasedOnParentClassMethodRectorTest extends AbstractRectorTestCase
+{
+    /**
+     * @dataProvider provideData()
+     */
+    public function test(SmartFileInfo $fileInfo): void
+    {
+        $this->doTestFileInfo($fileInfo);
+    }
+
+    /**
+     * @return Iterator<SmartFileInfo>
+     */
+    public function provideData(): Iterator
+    {
+        return $this->yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/configured_rule.php';
+    }
+}
diff --git a/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Fixture/extended_class.php.inc b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Fixture/extended_class.php.inc
new file mode 100644
index 00000000000..12bc4947185
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Fixture/extended_class.php.inc
@@ -0,0 +1,25 @@
+<?php
+
+use Rector\Tests\TypeDeclaration\Rector\ClassMethod\AddReturnTypeDeclarationBasedOnParentClassMethodRector\Source\SomeClassWithReturnType;
+
+class MyClass extends SomeClassWithReturnType
+{
+    public function run()
+    {
+    }
+}
+
+?>
+-----
+<?php
+
+use Rector\Tests\TypeDeclaration\Rector\ClassMethod\AddReturnTypeDeclarationBasedOnParentClassMethodRector\Source\SomeClassWithReturnType;
+
+class MyClass extends SomeClassWithReturnType
+{
+    public function run(): int
+    {
+    }
+}
+
+?>
diff --git a/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Fixture/extended_class_no_type.php.inc b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Fixture/extended_class_no_type.php.inc
new file mode 100644
index 00000000000..90eaf3dbabb
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Fixture/extended_class_no_type.php.inc
@@ -0,0 +1,25 @@
+<?php
+
+use Rector\Tests\TypeDeclaration\Rector\ClassMethod\AddReturnTypeDeclarationBasedOnParentClassMethodRector\Source\SomeClassWithoutReturnType;
+
+class MyClass extends SomeClassWithoutReturnType
+{
+    public function run()
+    {
+    }
+}
+
+?>
+-----
+<?php
+
+use Rector\Tests\TypeDeclaration\Rector\ClassMethod\AddReturnTypeDeclarationBasedOnParentClassMethodRector\Source\SomeClassWithoutReturnType;
+
+class MyClass extends SomeClassWithoutReturnType
+{
+    public function run()
+    {
+    }
+}
+
+?>
diff --git a/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Fixture/extended_interface.php.inc b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Fixture/extended_interface.php.inc
new file mode 100644
index 00000000000..bcc22253170
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Fixture/extended_interface.php.inc
@@ -0,0 +1,25 @@
+<?php
+
+use Rector\Tests\TypeDeclaration\Rector\ClassMethod\AddReturnTypeDeclarationBasedOnParentClassMethodRector\Source\SomeInterfaceWithReturnType;
+
+abstract class MyClass implements SomeInterfaceWithReturnType
+{
+    public function run()
+    {
+    }
+}
+
+?>
+-----
+<?php
+
+use Rector\Tests\TypeDeclaration\Rector\ClassMethod\AddReturnTypeDeclarationBasedOnParentClassMethodRector\Source\SomeInterfaceWithReturnType;
+
+abstract class MyClass implements SomeInterfaceWithReturnType
+{
+    public function run(): string
+    {
+    }
+}
+
+?>
diff --git a/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Source/SomeClassWithReturnType.php b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Source/SomeClassWithReturnType.php
new file mode 100644
index 00000000000..e42c7a77654
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Source/SomeClassWithReturnType.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\TypeDeclaration\Rector\ClassMethod\AddReturnTypeDeclarationBasedOnParentClassMethodRector\Source;
+
+class SomeClassWithReturnType
+{
+    public function run(): int
+    {
+      return 5;
+    }
+}
diff --git a/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Source/SomeClassWithoutReturnType.php b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Source/SomeClassWithoutReturnType.php
new file mode 100644
index 00000000000..b3bd426f1e2
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Source/SomeClassWithoutReturnType.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\TypeDeclaration\Rector\ClassMethod\AddReturnTypeDeclarationBasedOnParentClassMethodRector\Source;
+
+class SomeClassWithoutReturnType
+{
+    public function run()
+    {
+      return 5;
+    }
+}
diff --git a/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Source/SomeInterfaceWithReturnType.php b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Source/SomeInterfaceWithReturnType.php
new file mode 100644
index 00000000000..f0a04ea1b7b
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/Source/SomeInterfaceWithReturnType.php
@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\TypeDeclaration\Rector\ClassMethod\AddReturnTypeDeclarationBasedOnParentClassMethodRector\Source;
+
+interface SomeInterfaceWithReturnType
+{
+    public function run(): string;
+}
diff --git a/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/config/configured_rule.php b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/config/configured_rule.php
new file mode 100644
index 00000000000..508bc90f4bc
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector/config/configured_rule.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\Core\ValueObject\PhpVersionFeature;
+use Rector\TypeDeclaration\Rector\ClassMethod\AddReturnTypeDeclarationBasedOnParentClassMethodRector;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->rule(AddReturnTypeDeclarationBasedOnParentClassMethodRector::class);
+
+    $rectorConfig->phpVersion(PhpVersionFeature::MIXED_TYPE);
+};
diff --git a/rules/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector.php b/rules/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector.php
new file mode 100644
index 00000000000..253a1ebebbc
--- /dev/null
+++ b/rules/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationBasedOnParentClassMethodRector.php
@@ -0,0 +1,160 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\TypeDeclaration\Rector\ClassMethod;
+
+use PhpParser\Node;
+use PhpParser\Node\Stmt\Class_;
+use PhpParser\Node\Stmt\ClassMethod;
+use PHPStan\Reflection\MethodReflection;
+use PHPStan\Type\MixedType;
+use PHPStan\Type\ObjectType;
+use PHPStan\Type\Type;
+use Rector\Core\Php\PhpVersionProvider;
+use Rector\Core\PhpParser\AstResolver;
+use Rector\Core\Rector\AbstractRector;
+use Rector\Core\ValueObject\MethodName;
+use Rector\Core\ValueObject\PhpVersionFeature;
+use Rector\NodeTypeResolver\Node\AttributeKey;
+use Rector\PHPStanStaticTypeMapper\Enum\TypeKind;
+use Rector\VendorLocker\ParentClassMethodTypeOverrideGuard;
+use Rector\VersionBonding\Contract\MinPhpVersionInterface;
+use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
+use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
+
+/**
+ * @changelog https://wiki.php.net/rfc/lsp_errors
+ * @see \Rector\Tests\TypeDeclaration\Rector\ClassMethod\AddReturnTypeDeclarationBasedOnParentClassMethodRector\AddReturnTypeDeclarationBasedOnParentClassMethodRectorTest
+ */
+final class AddReturnTypeDeclarationBasedOnParentClassMethodRector extends AbstractRector implements MinPhpVersionInterface
+{
+    public function __construct(
+        private readonly ParentClassMethodTypeOverrideGuard $parentClassMethodTypeOverrideGuard,
+        private readonly AstResolver $astResolver,
+        private readonly PhpVersionProvider $phpVersionProvider,
+    ) {
+    }
+
+    public function provideMinPhpVersion(): int
+    {
+        return PhpVersionFeature::FATAL_ERROR_ON_INCOMPATIBLE_METHOD_SIGNATURE;
+    }
+
+    public function getRuleDefinition(): RuleDefinition
+    {
+        return new RuleDefinition('Add missing return type declaration based on parent class method', [
+            new CodeSample(
+                <<<'CODE_SAMPLE'
+class A
+{
+    public function execute($foo): int
+    {
+    }
+}
+
+class B extends A{
+    public function execute()
+    {
+    }
+}
+CODE_SAMPLE
+,
+                <<<'CODE_SAMPLE'
+class A
+{
+    public function execute($foo): int
+    {
+    }
+}
+
+class B extends A{
+    public function execute($foo): int
+    {
+    }
+}
+CODE_SAMPLE
+            ),
+        ]);
+    }
+
+    /**
+     * @return array<class-string<Node>>
+     */
+    public function getNodeTypes(): array
+    {
+        return [ClassMethod::class];
+    }
+
+    /**
+     * @param ClassMethod $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        if ($this->nodeNameResolver->isName($node, MethodName::CONSTRUCT)) {
+            return null;
+        }
+
+        $parentMethodReflection = $this->parentClassMethodTypeOverrideGuard->getParentClassMethod($node);
+        if (! $parentMethodReflection instanceof MethodReflection) {
+            return null;
+        }
+
+        $parentClassMethod = $this->astResolver->resolveClassMethodFromMethodReflection($parentMethodReflection);
+
+        if (! $parentClassMethod instanceof ClassMethod) {
+            return null;
+        }
+
+        if ($parentClassMethod->isPrivate()) {
+            return null;
+        }
+
+        $parentClassMethodReturnType = $parentClassMethod->getReturnType();
+        if ($parentClassMethodReturnType === null) {
+            return null;
+        }
+
+        $parentClassMethodReturnType = $this->staticTypeMapper->mapPhpParserNodePHPStanType(
+            $parentClassMethodReturnType
+        );
+
+        return $this->processClassMethodReturnType($node, $parentClassMethodReturnType);
+    }
+
+    private function processClassMethodReturnType(ClassMethod $classMethod, Type $parentType): ?ClassMethod
+    {
+        if ($parentType instanceof MixedType) {
+            $class = $classMethod->getAttribute(AttributeKey::PARENT_NODE);
+            if (! $class instanceof Class_) {
+                return null;
+            }
+
+            $className = (string) $this->nodeNameResolver->getName($class);
+            $currentObjectType = new ObjectType($className);
+            if (! $parentType->equals($currentObjectType) && $classMethod->returnType !== null) {
+                return null;
+            }
+        }
+
+        // remove it
+        if ($parentType instanceof MixedType && ! $this->phpVersionProvider->isAtLeastPhpVersion(
+            PhpVersionFeature::MIXED_TYPE
+        )) {
+            $classMethod->returnType = null;
+            return null;
+        }
+
+        // already set and sub type or equal → no change
+        if ($this->parentClassMethodTypeOverrideGuard->shouldSkipReturnTypeChange($classMethod, $parentType)) {
+            return null;
+        }
+
+        $classMethod->returnType = $this->staticTypeMapper->mapPHPStanTypeToPhpParserNode(
+            $parentType,
+            TypeKind::RETURN
+        );
+
+        return $classMethod;
+    }
+}
diff --git a/rules/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationRector.php b/rules/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationRector.php
index 298a0db7d22..44ca19d1cc2 100644
--- a/rules/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationRector.php
+++ b/rules/TypeDeclaration/Rector/ClassMethod/AddReturnTypeDeclarationRector.php
@@ -16,9 +16,9 @@
 use Rector\Core\Rector\AbstractRector;
 use Rector\Core\ValueObject\PhpVersionFeature;
 use Rector\NodeTypeResolver\Node\AttributeKey;
-use Rector\NodeTypeResolver\TypeComparator\TypeComparator;
 use Rector\PHPStanStaticTypeMapper\Enum\TypeKind;
 use Rector\TypeDeclaration\ValueObject\AddReturnTypeDeclaration;
+use Rector\VendorLocker\ParentClassMethodTypeOverrideGuard;
 use Symplify\RuleDocGenerator\ValueObject\CodeSample\ConfiguredCodeSample;
 use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
 use Webmozart\Assert\Assert;
@@ -36,8 +36,8 @@ final class AddReturnTypeDeclarationRector extends AbstractRector implements Con
     private bool $hasChanged = false;
 
     public function __construct(
-        private readonly TypeComparator $typeComparator,
         private readonly PhpVersionProvider $phpVersionProvider,
+        private readonly ParentClassMethodTypeOverrideGuard $parentClassMethodTypeOverrideGuard
     ) {
     }
 
@@ -142,7 +142,7 @@ private function processClassMethodNodeWithTypehints(
         }
 
         // already set and sub type or equal → no change
-        if ($this->shouldSkipType($classMethod, $newType)) {
+        if ($this->parentClassMethodTypeOverrideGuard->shouldSkipReturnTypeChange($classMethod, $newType)) {
             return;
         }
 
@@ -150,19 +150,4 @@ private function processClassMethodNodeWithTypehints(
 
         $this->hasChanged = true;
     }
-
-    private function shouldSkipType(ClassMethod $classMethod, Type $newType): bool
-    {
-        if ($classMethod->returnType === null) {
-            return false;
-        }
-
-        $currentReturnType = $this->staticTypeMapper->mapPhpParserNodePHPStanType($classMethod->returnType);
-
-        if ($this->typeComparator->isSubtype($currentReturnType, $newType)) {
-            return true;
-        }
-
-        return $this->typeComparator->areTypesEqual($currentReturnType, $newType);
-    }
 }