diff --git a/core/modules/options/lib/Drupal/options/Plugin/Field/FieldType/ListItemBase.php b/core/modules/options/lib/Drupal/options/Plugin/Field/FieldType/ListItemBase.php
index 662169a..5b9e8fb 100644
--- a/core/modules/options/lib/Drupal/options/Plugin/Field/FieldType/ListItemBase.php
+++ b/core/modules/options/lib/Drupal/options/Plugin/Field/FieldType/ListItemBase.php
@@ -148,7 +148,7 @@ public function settingsForm(array $form, array &$form_state, $has_data) {
     $element['allowed_values_function'] = array(
       '#type' => 'item',
       '#title' => t('Allowed values list'),
-      '#markup' => t('The value of this field is being determined by the %function function and may not be changed.', array('%function' => $settings['allowed_values_function'])),
+      '#markup' => t('The value of this field is being determined by the %function function and may not be changed.', array('%function' => $allowed_values_function)),
       '#access' => !empty($allowed_values_function),
       '#value' => $allowed_values_function,
     );