diff -u b/core/modules/content_translation/src/Plugin/migrate/source/d6/BoxTranslation.php b/core/modules/content_translation/src/Plugin/migrate/source/d6/BoxTranslation.php
--- b/core/modules/content_translation/src/Plugin/migrate/source/d6/BoxTranslation.php
+++ b/core/modules/content_translation/src/Plugin/migrate/source/d6/BoxTranslation.php
@@ -2,7 +2,6 @@
 
 namespace Drupal\content_translation\Plugin\migrate\source\d6;
 
-use Drupal\migrate\MigrateException;
 use Drupal\migrate\Row;
 use Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase;