diff --git a/core/includes/entity.inc b/core/includes/entity.inc
index 07f0fce..8f4580a 100644
--- a/core/includes/entity.inc
+++ b/core/includes/entity.inc
@@ -486,7 +486,7 @@ function entity_form_state_defaults(EntityInterface $entity, $operation = 'defau
   $controller = \Drupal::entityManager()->getFormController($entity->entityType(), $operation);
   $controller->setEntity($entity);
   $form_state['build_info']['callback_object'] = $controller;
-  $form_state['build_info']['base_form_id'] = $controller->getBaseFormID();
+  $form_state['build_info']['base_form_id'] = $controller->getBaseFormId();
   $form_state['build_info']['args'] = array();
   return $form_state;
 }
diff --git a/core/includes/form.inc b/core/includes/form.inc
index 2f9dc7f..84f6411 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -129,7 +129,7 @@ function _drupal_form_id($form_arg, &$form_state) {
   if (is_object($form_arg) && $form_arg instanceof FormInterface) {
     $form_state['build_info']['callback_object'] = $form_arg;
     if ($form_arg instanceof BaseFormIdInterface) {
-      $form_state['build_info']['base_form_id'] = $form_arg->getBaseFormID();
+      $form_state['build_info']['base_form_id'] = $form_arg->getBaseFormId();
     }
     return $form_arg->getFormId();
   }
diff --git a/core/lib/Drupal/Core/Entity/ContentEntityConfirmFormBase.php b/core/lib/Drupal/Core/Entity/ContentEntityConfirmFormBase.php
index c43cd9c..4bf745c 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityConfirmFormBase.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityConfirmFormBase.php
@@ -18,7 +18,7 @@
   /**
    * {@inheritdoc}
    */
-  public function getBaseFormID() {
+  public function getBaseFormId() {
     return $this->entity->entityType() . '_confirm_form';
   }
 
diff --git a/core/lib/Drupal/Core/Entity/EntityConfirmFormBase.php b/core/lib/Drupal/Core/Entity/EntityConfirmFormBase.php
index 83091a3..b2dfa5d 100644
--- a/core/lib/Drupal/Core/Entity/EntityConfirmFormBase.php
+++ b/core/lib/Drupal/Core/Entity/EntityConfirmFormBase.php
@@ -19,7 +19,7 @@
   /**
    * {@inheritdoc}
    */
-  public function getBaseFormID() {
+  public function getBaseFormId() {
     return $this->entity->entityType() . '_confirm_form';
   }
 
diff --git a/core/lib/Drupal/Core/Entity/EntityFormController.php b/core/lib/Drupal/Core/Entity/EntityFormController.php
index 064250f..414ee6d 100644
--- a/core/lib/Drupal/Core/Entity/EntityFormController.php
+++ b/core/lib/Drupal/Core/Entity/EntityFormController.php
@@ -57,7 +57,7 @@ public function setOperation($operation) {
   /**
    * {@inheritdoc}
    */
-  public function getBaseFormID() {
+  public function getBaseFormId() {
     // Assign ENTITYTYPE_form as base form ID to invoke corresponding
     // hook_form_alter(), #validate, #submit, and #theme callbacks, but only if
     // it is different from the actual form ID, since callbacks would be invoked
diff --git a/core/lib/Drupal/Core/Form/BaseFormIdInterface.php b/core/lib/Drupal/Core/Form/BaseFormIdInterface.php
index f948aac..1d7b212 100644
--- a/core/lib/Drupal/Core/Form/BaseFormIdInterface.php
+++ b/core/lib/Drupal/Core/Form/BaseFormIdInterface.php
@@ -21,6 +21,6 @@
    * @return string|false
    *   The string identifying the base form or FALSE if this is not a base form.
    */
-  public function getBaseFormID();
+  public function getBaseFormId();
 
 }
diff --git a/core/modules/book/lib/Drupal/book/Form/BookOutlineForm.php b/core/modules/book/lib/Drupal/book/Form/BookOutlineForm.php
index d0960f4..c2e8363 100644
--- a/core/modules/book/lib/Drupal/book/Form/BookOutlineForm.php
+++ b/core/modules/book/lib/Drupal/book/Form/BookOutlineForm.php
@@ -50,7 +50,7 @@ public static function create(ContainerInterface $container) {
   /**
    * {@inheritdoc}
    */
-  public function getBaseFormID() {
+  public function getBaseFormId() {
     return FALSE;
   }