diff --git a/src/CoreShop/Bundle/ResourceBundle/EventListener/DeepCopySubscriber.php b/src/CoreShop/Bundle/ResourceBundle/EventListener/DeepCopySubscriber.php
index 39c2808123..eb46756014 100644
--- a/src/CoreShop/Bundle/ResourceBundle/EventListener/DeepCopySubscriber.php
+++ b/src/CoreShop/Bundle/ResourceBundle/EventListener/DeepCopySubscriber.php
@@ -70,7 +70,7 @@ public function addDoctrineCollectionFilter(GenericEvent $event): void
              */
             $copier->addFilter(
                 new PimcoreFieldCollectionDefinitionReplaceFilter(
-                    function (AbstractData $object, Data $fieldDefinition, $property, $currentValue) {
+                    function (AbstractData $object, Data $fieldDefinition, mixed $property, mixed $currentValue): mixed {
                         if ($fieldDefinition instanceof Data\CustomVersionMarshalInterface) {
                             return $fieldDefinition->marshalVersion($object->getObject(), $currentValue);
                         }
@@ -85,7 +85,7 @@ function (AbstractData $object, Data $fieldDefinition, $property, $currentValue)
         if (($context['source'] ?? false) === 'Pimcore\Model\Version::unmarshalData') {
             $copier->addFilter(
                 new PimcoreFieldCollectionDefinitionReplaceFilter(
-                    function (AbstractData $object, Data $fieldDefinition, $property, $currentValue) {
+                    function (AbstractData $object, Data $fieldDefinition, mixed $property, mixed $currentValue): mixed {
                         if ($fieldDefinition instanceof Data\CustomVersionMarshalInterface) {
                             return $fieldDefinition->unmarshalVersion($object->getObject(), $currentValue);
                         }