diff --git a/core/lib/Drupal.php b/core/lib/Drupal.php
index d1e4a05..de931a5 100644
--- a/core/lib/Drupal.php
+++ b/core/lib/Drupal.php
@@ -254,6 +254,8 @@ public static function currentUser() {
    *   The entity manager service.
    *
    * @deprecated in Drupal 8.0.0, will be removed before Drupal 9.0.0.
+   *   Most of the time \Drupal::entityTypeManager() is supposed to be used
+   *   instead.
    */
   public static function entityManager() {
     return static::getContainer()->get('entity.manager');
diff --git a/core/lib/Drupal/Core/Controller/ControllerBase.php b/core/lib/Drupal/Core/Controller/ControllerBase.php
index 9ac6791..544e247 100644
--- a/core/lib/Drupal/Core/Controller/ControllerBase.php
+++ b/core/lib/Drupal/Core/Controller/ControllerBase.php
@@ -126,6 +126,8 @@ public static function create(ContainerInterface $container) {
    *   The entity manager service.
    *
    * @deprecated in Drupal 8.0.0, will be removed before Drupal 9.0.0.
+   *   Most of the time static::entityTypeManager() is supposed to be used
+   *   instead.
    */
   protected function entityManager() {
     if (!$this->entityManager) {
diff --git a/core/lib/Drupal/Core/Entity/Entity.php b/core/lib/Drupal/Core/Entity/Entity.php
index bebfeb8..0798823 100644
--- a/core/lib/Drupal/Core/Entity/Entity.php
+++ b/core/lib/Drupal/Core/Entity/Entity.php
@@ -74,6 +74,8 @@ public function __construct(array $values, $entity_type) {
    * @return \Drupal\Core\Entity\EntityManagerInterface
    *
    * @deprecated in Drupal 8.0.0, will be removed before Drupal 9.0.0.
+   *   Most of the time static::entityTypeManager() is supposed to be used
+   *   instead.
    */
   protected function entityManager() {
     return \Drupal::entityManager();