diff --git a/core/modules/field_ui/field_ui.admin.inc b/core/modules/field_ui/field_ui.admin.inc
index c22fe21..30d9a9c 100644
--- a/core/modules/field_ui/field_ui.admin.inc
+++ b/core/modules/field_ui/field_ui.admin.inc
@@ -404,8 +404,8 @@ function field_ui_field_overview_form($form, &$form_state, $entity_type, $bundle
       ),
     );
 
-    if (!empty($instance['locked'])) {
-      $table[$name]['edit'] = array('#value' => t('Locked'));
+    if (!empty($field['locked'])) {
+      $table[$name]['edit'] = array('#markup' => t('Locked'));
       $table[$name]['delete'] = array();
       $table[$name]['#attributes']['class'][] = 'menu-disabled';
     }