@@ -74,7 +74,7 @@
         "symfony/framework-bundle": "^4.2",
         "symfony/mercure-bundle": "*",
         "symfony/messenger": "^4.2",
-        "symfony/phpunit-bridge": "^4.3.1",
+        "symfony/phpunit-bridge": "^4.3@dev",
         "symfony/routing": "^3.4 || ^4.0",
         "symfony/security-bundle": "^3.4 || ^4.0",
         "symfony/security-core": "^3.4 || ^4.0",
 
@@ -19,6 +19,7 @@
 use ApiPlatform\Core\Metadata\Resource\Factory\ResourceMetadataFactoryInterface;
 use ApiPlatform\Core\Security\ResourceAccessCheckerInterface;
 use ApiPlatform\Core\Util\ClassInfoTrait;
+use ApiPlatform\Core\Util\CloneTrait;
 use GraphQL\Type\Definition\ResolveInfo;
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
 
@@ -32,6 +33,7 @@
  */
 final class ItemResolver
 {
+    use CloneTrait;
     use ClassInfoTrait;
     use FieldsToAttributesTrait;
     use ResourceAccessCheckerTrait;
@@ -71,7 +73,7 @@ public function __invoke($source, $args, $context, ResolveInfo $info)
         $resourceMetadata = $this->resourceMetadataFactory->create($resourceClass);
         $this->canAccess($this->resourceAccessChecker, $resourceMetadata, $resourceClass, $info, [
             'object' => $item,
-            'previous_object' => clone $item,
+            'previous_object' => $this->clone($item),
         ], 'query');
 
         $normalizationContext = $resourceMetadata->getGraphqlAttribute('query', 'normalization_context', [], true);