diff --git a/core/modules/field/field.module b/core/modules/field/field.module
index 143e8c5..113acbe 100644
--- a/core/modules/field/field.module
+++ b/core/modules/field/field.module
@@ -135,7 +135,7 @@ function field_system_info_alter(&$info, Extension $file, $type) {
       // remains no actual, non-deleted fields)
       $non_deleted = FALSE;
       foreach ($field_storages as $field_storage) {
-        if (empty($field_storage->deleted)) {
+        if (!$field_storage->isDeleted()) {
           $non_deleted = TRUE;
           break;
         }
diff --git a/core/modules/field/src/Tests/reEnableModuleFieldTest.php b/core/modules/field/src/Tests/reEnableModuleFieldTest.php
index 2b8f4c1..2139f6e 100644
--- a/core/modules/field/src/Tests/reEnableModuleFieldTest.php
+++ b/core/modules/field/src/Tests/reEnableModuleFieldTest.php
@@ -39,6 +39,8 @@ protected function setUp() {
 
   /**
    * Test the behavior of a field module after being disabled and re-enabled.
+   *
+   * @see \field_system_info_alter()
    */
   function testReEnabledField() {
 
diff --git a/core/modules/field_ui/src/FieldConfigListBuilder.php b/core/modules/field_ui/src/FieldConfigListBuilder.php
index ea5170f..3535134 100644
--- a/core/modules/field_ui/src/FieldConfigListBuilder.php
+++ b/core/modules/field_ui/src/FieldConfigListBuilder.php
@@ -149,7 +149,7 @@ public function buildRow(EntityInterface $field_config) {
     // Add the operations.
     $row['data'] = $row['data'] + parent::buildRow($field_config);
 
-    if (!empty($field_storage->locked)) {
+    if ($field_storage->isLocked()) {
       $row['data']['operations'] = array('data' => array('#markup' => $this->t('Locked')));
       $row['class'][] = 'menu-disabled';
     }