diff --git a/core/lib/Drupal/Core/Entity/EntityTypeInterface.php b/core/lib/Drupal/Core/Entity/EntityTypeInterface.php
index 85f98ec..60a4436 100644
--- a/core/lib/Drupal/Core/Entity/EntityTypeInterface.php
+++ b/core/lib/Drupal/Core/Entity/EntityTypeInterface.php
@@ -222,6 +222,10 @@ public function getHandlerClass($handler_type);
    *   - access: The name of the class that is used for access checks. The class
    *     must implement \Drupal\Core\Entity\EntityAccessControlHandlerInterface.
    *     Defaults to \Drupal\Core\Entity\EntityAccessControlHandler.
+   *   - route_provider: (optional) A list of class names, keyed by a group
+   *     string, which will be used to define routes related to this entity
+   *     type. These classes must implement
+   *     \Drupal\Core\Entity\Routing\EntityRouteProviderInterface.
    */
   public function getHandlerClasses();