diff -u b/core/modules/migrate/src/Audit/IdAuditor.php b/core/modules/migrate/src/Audit/IdAuditor.php
--- b/core/modules/migrate/src/Audit/IdAuditor.php
+++ b/core/modules/migrate/src/Audit/IdAuditor.php
@@ -19,6 +19,8 @@
     $plugin_definition = $migration->getPluginDefinition();
 
     // If the migration does not opt into auditing, it passes.
+    // @todo Use $migration->isAuditable() when
+    // https://www.drupal.org/project/drupal/issues/2930832 is in.
     if (empty($plugin_definition['audit'])) {
       return AuditResult::pass($migration);
     }