diff --git a/src/bundle/DependencyInjection/Compiler/ValueObjectVisitorResolverPass.php b/src/bundle/DependencyInjection/Compiler/ValueObjectVisitorResolverPass.php
index 387bd281..5dd8d0f0 100644
--- a/src/bundle/DependencyInjection/Compiler/ValueObjectVisitorResolverPass.php
+++ b/src/bundle/DependencyInjection/Compiler/ValueObjectVisitorResolverPass.php
@@ -4,6 +4,7 @@
  * @copyright Copyright (C) Ibexa AS. All rights reserved.
  * @license For full copyright and license information view LICENSE file distributed with this source code.
  */
+declare(strict_types=1);
 
 namespace Ibexa\Bundle\Rest\DependencyInjection\Compiler;
 
diff --git a/src/contracts/Output/Generator.php b/src/contracts/Output/Generator.php
index 964572e2..fad34e10 100644
--- a/src/contracts/Output/Generator.php
+++ b/src/contracts/Output/Generator.php
@@ -140,9 +140,6 @@ public function startObjectElement(string $name, ?string $mediaTypeName = null):
         $this->attribute('media-type', $this->getMediaType($mediaTypeName));
     }
 
-    /**
-     * End object element.
-     */
     public function endObjectElement(string $name): void
     {
         $this->checkEndObjectElement($name);
@@ -157,9 +154,6 @@ public function endObjectElement(string $name): void
         $this->json = $this->json->getParent();
     }
 
-    /**
-     * Check start object element.
-     */
     protected function checkStartObjectElement(mixed $data): void
     {
         $this->checkStart('objectElement', $data, ['document', 'objectElement', 'hashElement', 'list']);
diff --git a/src/contracts/Output/ValueObjectVisitorResolver.php b/src/contracts/Output/ValueObjectVisitorResolver.php
index d23fc68e..1093f04b 100644
--- a/src/contracts/Output/ValueObjectVisitorResolver.php
+++ b/src/contracts/Output/ValueObjectVisitorResolver.php
@@ -10,7 +10,7 @@
 
 final class ValueObjectVisitorResolver implements ValueObjectVisitorResolverInterface
 {
-    /** @var array<class-string, ValueObjectVisitor> */
+    /** @var array<class-string, \Ibexa\Contracts\Rest\Output\ValueObjectVisitor> */
     private array $visitors;
 
     /**
diff --git a/src/contracts/Output/VisitorAdapterNormalizer.php b/src/contracts/Output/VisitorAdapterNormalizer.php
index 90fc6957..c42a0ef8 100644
--- a/src/contracts/Output/VisitorAdapterNormalizer.php
+++ b/src/contracts/Output/VisitorAdapterNormalizer.php
@@ -104,9 +104,7 @@ private function visitValueObject(
 
         $generator->reset();
         $generator->startDocument($object);
-
         $valueObjectVisitor->visit($visitor, $generator, $object);
-
         $generator->endDocument($object);
 
         $data = $generator->getData();
diff --git a/src/lib/Output/Generator/Data/ArrayList.php b/src/lib/Output/Generator/Data/ArrayList.php
index 962f0ebd..4f62c73c 100644
--- a/src/lib/Output/Generator/Data/ArrayList.php
+++ b/src/lib/Output/Generator/Data/ArrayList.php
@@ -8,7 +8,9 @@
 
 namespace Ibexa\Rest\Output\Generator\Data;
 
-final class ArrayList extends \ArrayObject implements DataObjectInterface
+use ArrayObject;
+
+final class ArrayList extends ArrayObject implements DataObjectInterface
 {
     private ?DataObjectInterface $parent;
 
diff --git a/src/lib/Output/Generator/Json/ArrayObject.php b/src/lib/Output/Generator/Json/ArrayObject.php
index 948024e0..23eaffa3 100644
--- a/src/lib/Output/Generator/Json/ArrayObject.php
+++ b/src/lib/Output/Generator/Json/ArrayObject.php
@@ -19,7 +19,7 @@
  * parent object it is assigned to again.
  */
 #[AllowDynamicProperties]
-class ArrayObject extends NativeArrayObject implements DataObjectInterface
+final class ArrayObject extends NativeArrayObject implements DataObjectInterface
 {
     /**
      * Reference to the parent node.
diff --git a/src/lib/Output/Generator/Json/JsonObject.php b/src/lib/Output/Generator/Json/JsonObject.php
index ff98cdb5..b53b65d6 100644
--- a/src/lib/Output/Generator/Json/JsonObject.php
+++ b/src/lib/Output/Generator/Json/JsonObject.php
@@ -18,12 +18,12 @@
  * parent object it is assigned to again.
  */
 #[AllowDynamicProperties]
-class JsonObject implements DataObjectInterface
+final class JsonObject implements DataObjectInterface
 {
     /**
      * Reference to the parent node.
      */
-    protected ?DataObjectInterface $_ref_parent;
+    private ?DataObjectInterface $_ref_parent;
 
     /**
      * Construct from optional parent node.
diff --git a/src/lib/Output/Normalizer/ArrayObjectNormalizer.php b/src/lib/Output/Normalizer/ArrayObjectNormalizer.php
index fc6994b8..f5b778ca 100644
--- a/src/lib/Output/Normalizer/ArrayObjectNormalizer.php
+++ b/src/lib/Output/Normalizer/ArrayObjectNormalizer.php
@@ -4,6 +4,7 @@
  * @copyright Copyright (C) Ibexa AS. All rights reserved.
  * @license For full copyright and license information view LICENSE file distributed with this source code.
  */
+declare(strict_types=1);
 
 namespace Ibexa\Rest\Output\Normalizer;
 
diff --git a/src/lib/Output/Normalizer/JsonObjectNormalizer.php b/src/lib/Output/Normalizer/JsonObjectNormalizer.php
index c703959d..4a00ae77 100644
--- a/src/lib/Output/Normalizer/JsonObjectNormalizer.php
+++ b/src/lib/Output/Normalizer/JsonObjectNormalizer.php
@@ -4,6 +4,7 @@
  * @copyright Copyright (C) Ibexa AS. All rights reserved.
  * @license For full copyright and license information view LICENSE file distributed with this source code.
  */
+declare(strict_types=1);
 
 namespace Ibexa\Rest\Output\Normalizer;