diff --git a/core/modules/field_ui/src/Form/FieldConfigEditForm.php b/core/modules/field_ui/src/Form/FieldConfigEditForm.php
index 8a3cd54..8343fff 100644
--- a/core/modules/field_ui/src/Form/FieldConfigEditForm.php
+++ b/core/modules/field_ui/src/Form/FieldConfigEditForm.php
@@ -35,18 +35,20 @@ class FieldConfigEditForm extends EntityForm {
   public function form(array $form, FormStateInterface $form_state) {
     $form = parent::form($form, $form_state);
 
-    $field_storage = $this->entity->getFieldStorageDefinition();
+    /** @var \Drupal\field\Entity\FieldConfig $field */
+    $field = $this->entity;
+    $field_storage = $field->getFieldStorageDefinition();
     $bundles = $this->entityManager->getBundleInfo($this->entity->getTargetEntityTypeId());
 
     $form_title = $this->t('%field settings for %bundle', array(
-      '%field' => $this->entity->getLabel(),
-      '%bundle' => $bundles[$this->entity->bundle]['label'],
+      '%field' => $field->getLabel(),
+      '%bundle' => $bundles[$field->getBundle()]['label'],
     ));
     $form['#title'] = $form_title;
 
     if ($field_storage->isLocked()) {
       $form['locked'] = array(
-        '#markup' => $this->t('The field %field is locked and cannot be edited.', array('%field' => $this->entity->getLabel())),
+        '#markup' => $this->t('The field %field is locked and cannot be edited.', array('%field' => $field->getLabel())),
       );
       return $form;
     }
@@ -55,7 +57,7 @@ public function form(array $form, FormStateInterface $form_state) {
     $form['label'] = array(
       '#type' => 'textfield',
       '#title' => $this->t('Label'),
-      '#default_value' => $this->entity->getLabel() ?: $field_storage->getName(),
+      '#default_value' => $field->getLabel() ?: $field_storage->getName(),
       '#required' => TRUE,
       '#weight' => -20,
     );
@@ -63,7 +65,7 @@ public function form(array $form, FormStateInterface $form_state) {
     $form['description'] = array(
       '#type' => 'textarea',
       '#title' => $this->t('Help text'),
-      '#default_value' => $this->entity->getDescription(),
+      '#default_value' => $field->getDescription(),
       '#rows' => 5,
       '#description' => $this->t('Instructions to present to the user below this field on the editing form.<br />Allowed HTML tags: @tags', array('@tags' => $this->displayAllowedTags())) . '<br />' . $this->t('This field supports tokens.'),
       '#weight' => -10,
@@ -72,18 +74,18 @@ public function form(array $form, FormStateInterface $form_state) {
     $form['required'] = array(
       '#type' => 'checkbox',
       '#title' => $this->t('Required field'),
-      '#default_value' => $this->entity->isRequired(),
+      '#default_value' => $field->isRequired(),
       '#weight' => -5,
     );
 
     // Create an arbitrary entity object (used by the 'default value' widget).
     $ids = (object) array(
       'entity_type' => $this->entity->getTargetEntityTypeId(),
-      'bundle' => $this->entity->bundle,
+      'bundle' => $field->getBundle(),
       'entity_id' => NULL
     );
     $form['#entity'] = _field_create_entity_from_ids($ids);
-    $items = $form['#entity']->get($this->entity->getName());
+    $items = $form['#entity']->get($field->getName());
     $item = $items->first() ?: $items->appendItem();
 
     // Add field settings for the field type and a container for third party
@@ -125,7 +127,7 @@ protected function actions(array $form, FormStateInterface $form_state) {
       $target_entity_type = $this->entityManager->getDefinition($this->entity->getTargetEntityTypeId());
       $route_parameters = [
         'field_config' => $this->entity->id(),
-      ] + FieldUI::getRouteBundleParameter($target_entity_type, $this->entity->bundle);
+      ] + FieldUI::getRouteBundleParameter($target_entity_type, $this->entity->getBundle());
       $url = new Url('entity.field_config.' . $target_entity_type->id() . '_field_delete_form', $route_parameters);
 
       if ($this->getRequest()->query->has('destination')) {
@@ -188,7 +190,7 @@ public function save(array $form, FormStateInterface $form_state) {
       $form_state->setRedirectUrl($next_destination);
     }
     else {
-      $form_state->setRedirectUrl(FieldUI::getOverviewRouteInfo($this->entity->getTargetEntityTypeId(), $this->entity->bundle));
+      $form_state->setRedirectUrl(FieldUI::getOverviewRouteInfo($this->entity->getTargetEntityTypeId(), $this->entity->getBundle()));
     }
   }