diff --git a/core/modules/migrate/src/MigrateExecutable.php b/core/modules/migrate/src/MigrateExecutable.php
index bd779eb..4fa099b 100644
--- a/core/modules/migrate/src/MigrateExecutable.php
+++ b/core/modules/migrate/src/MigrateExecutable.php
@@ -97,6 +97,8 @@ class MigrateExecutable implements MigrateExecutableInterface {
   /**
    * Migration message service.
    *
+   * @todo Make it protected: https://www.drupal.org/node/2822663
+   *
    * @var \Drupal\migrate\MigrateMessageInterface
    */
   public $message;