diff --git a/Classes/FormDataProvider/ValuePickerItemDataProvider.php b/Classes/FormDataProvider/ValuePickerItemDataProvider.php
index 92785cd..ce991c8 100644
--- a/Classes/FormDataProvider/ValuePickerItemDataProvider.php
+++ b/Classes/FormDataProvider/ValuePickerItemDataProvider.php
@@ -54,7 +54,7 @@ class ValuePickerItemDataProvider implements FormDataProviderInterface
                 $result['processedTca']['columns']['skilldisplay_skillset']['config']['valuePicker']['items'][] =
                     [
                         $skillSet->getName(),
-                        $skillSet->getId(),
+                        (string)$skillSet->getId(),
                     ];
             }
         }