diff --git a/src/DataObject/Attribute/Parameter/Query/ClassNameParameter.php b/src/DataObject/Attribute/Parameter/Query/ClassNameParameter.php
deleted file mode 100644
index 6078cb721..000000000
--- a/src/DataObject/Attribute/Parameter/Query/ClassNameParameter.php
+++ /dev/null
@@ -1,44 +0,0 @@
-<?php
-declare(strict_types=1);
-
-/**
- * Pimcore
- *
- * This source file is available under two different licenses:
- * - GNU General Public License version 3 (GPLv3)
- * - Pimcore Commercial License (PCL)
- * Full copyright and license information is available in
- * LICENSE.md which is distributed with this source code.
- *
- *  @copyright  Copyright (c) Pimcore GmbH (http://www.pimcore.org)
- *  @license    http://www.pimcore.org/license     GPLv3 and PCL
- */
-
-namespace Pimcore\Bundle\StudioBackendBundle\DataObject\Attribute\Parameter\Query;
-
-use Attribute;
-use OpenApi\Attributes\QueryParameter;
-use OpenApi\Attributes\Schema;
-use Pimcore\Model\DataObject\ClassDefinition;
-
-#[Attribute(Attribute::TARGET_METHOD)]
-final class ClassNameParameter extends QueryParameter
-{
-    public function __construct()
-    {
-        // TODO Find better concept for this
-        $classDefinitions = new ClassDefinition\Listing();
-
-        parent::__construct(
-            name: 'className',
-            description: 'Filter by class.',
-            in: 'query',
-            required: false,
-            schema: new Schema(
-                type: 'string',
-                enum:  array_map(static fn (ClassDefinition $def) => $def->getName(), $classDefinitions->load()),
-                example: null
-            ),
-        );
-    }
-}
diff --git a/src/DataObject/Controller/TreeController.php b/src/DataObject/Controller/TreeController.php
index cda52da8d..fdbb08ca6 100644
--- a/src/DataObject/Controller/TreeController.php
+++ b/src/DataObject/Controller/TreeController.php
@@ -19,7 +19,6 @@
 use OpenApi\Attributes\Get;
 use Pimcore\Bundle\StudioBackendBundle\Controller\AbstractApiController;
 use Pimcore\Bundle\StudioBackendBundle\DataIndex\Request\DataObjectParameters;
-use Pimcore\Bundle\StudioBackendBundle\DataObject\Attribute\Parameter\Query\ClassNameParameter;
 use Pimcore\Bundle\StudioBackendBundle\DataObject\Attribute\Response\Property\AnyOfDataObjects;
 use Pimcore\Bundle\StudioBackendBundle\DataObject\Service\DataObjectServiceInterface;
 use Pimcore\Bundle\StudioBackendBundle\Exception\Api\AccessDeniedException;
@@ -37,6 +36,7 @@
 use Pimcore\Bundle\StudioBackendBundle\OpenApi\Attribute\Parameter\Query\PathIncludeDescendantsParameter;
 use Pimcore\Bundle\StudioBackendBundle\OpenApi\Attribute\Parameter\Query\PathIncludeParentParameter;
 use Pimcore\Bundle\StudioBackendBundle\OpenApi\Attribute\Parameter\Query\PathParameter;
+use Pimcore\Bundle\StudioBackendBundle\OpenApi\Attribute\Parameter\Query\TextFieldParameter;
 use Pimcore\Bundle\StudioBackendBundle\OpenApi\Attribute\Response\Content\CollectionJson;
 use Pimcore\Bundle\StudioBackendBundle\OpenApi\Attribute\Response\DefaultResponses;
 use Pimcore\Bundle\StudioBackendBundle\OpenApi\Attribute\Response\SuccessResponse;
@@ -85,12 +85,17 @@ public function __construct(
     #[PathParameter]
     #[PathIncludeParentParameter]
     #[PathIncludeDescendantsParameter]
-    #[ClassNameParameter]
+    #[TextFieldParameter(
+        name: 'className',
+        description: 'Filter by class.',
+        example: 'Car'
+    )]
     #[SuccessResponse(
         description: 'data_object_get_tree_success_response',
         content: new CollectionJson(new AnyOfDataObjects())
     )]
     #[DefaultResponses([
+        HttpResponseCodes::BAD_REQUEST,
         HttpResponseCodes::UNAUTHORIZED,
         HttpResponseCodes::NOT_FOUND,
     ])]