diff --git a/modules/json_form_widget/src/ArrayHelper.php b/modules/json_form_widget/src/ArrayHelper.php
index 799b4b1513..e44ce458e5 100644
--- a/modules/json_form_widget/src/ArrayHelper.php
+++ b/modules/json_form_widget/src/ArrayHelper.php
@@ -129,7 +129,7 @@ public function handleArrayElement(array $definition, ?array $data, FormStateInt
    * @return array
    *   Render array for the array parent element.
    */
-  protected function buildArrayParentElement($definition, $is_required, $context_name) {
+  protected function buildArrayParentElement(array $definition, bool $is_required, string $context_name) {
     $element = [
       '#type' => 'fieldset',
       '#title' => ($definition['schema']->title ?? $definition['name']),
@@ -204,18 +204,6 @@ protected function buildSimpleArrayElement(array $definition, $data, array $cont
     ];
   }
 
-  /**
-   * Flatten array element fieldset w/buttons for processing.
-   *
-   * @param array $element
-   *   A form element.
-   */
-  public static function flattenArrayElementFieldset(array &$element): void {
-    if (isset($element['field']) && $element['#type'] == 'fieldset') {
-      $element = ['#required' => ($element['#required'] ?? FALSE)] + $element['field'];
-    }
-  }
-
   /**
    * Returns single complex element from array.
    *
diff --git a/modules/json_form_widget/src/WidgetRouter.php b/modules/json_form_widget/src/WidgetRouter.php
index 00a0663558..72c0183f03 100644
--- a/modules/json_form_widget/src/WidgetRouter.php
+++ b/modules/json_form_widget/src/WidgetRouter.php
@@ -147,7 +147,7 @@ public function handleListElement(mixed $spec, array $element) {
    *   The dropdown element configured.
    */
   public function getDropdownElement(mixed $element, mixed $spec, mixed $titleProperty = FALSE) {
-    ArrayHelper::flattenArrayElementFieldset($element);
+    static::flattenArrayFieldset($element);
     $element['#type'] = $this->getSelectType($spec);
     $element['#options'] = $this->getDropdownOptions($spec->source, $titleProperty);
     if ($element['#type'] === 'select_or_other_select') {
@@ -166,6 +166,18 @@ public function getDropdownElement(mixed $element, mixed $spec, mixed $titleProp
     return $element;
   }
 
+  /**
+   * Flatten array element fieldset w/buttons for processing.
+   *
+   * @param array $element
+   *   A form element.
+   */
+  public static function flattenArrayFieldset(array &$element): void {
+    if (isset($element['field']) && $element['#type'] == 'fieldset') {
+      $element = ['#required' => ($element['#required'] ?? FALSE)] + $element['field'];
+    }
+  }
+
   /**
    * Helper function to get type of pick list.
    *