diff --git a/modules/tome_sync/src/Normalizer/PathAliasNormalizer.php b/modules/tome_sync/src/Normalizer/PathAliasNormalizer.php
--- a/modules/tome_sync/src/Normalizer/PathAliasNormalizer.php
+++ b/modules/tome_sync/src/Normalizer/PathAliasNormalizer.php
@@ -39,7 +39,7 @@ class PathAliasNormalizer extends ContentEntityNormalizer {
    * @param \Drupal\Core\Entity\EntityRepositoryInterface $entity_repository
    *   The entity field manager.
    */
-  public function __construct(EntityTypeManagerInterface $entity_type_manager, EntityTypeRepositoryInterface $entity_type_repository = NULL, EntityFieldManagerInterface $entity_field_manager = NULL, EntityRepositoryInterface $entity_repository) {
+  public function __construct(EntityTypeManagerInterface $entity_type_manager, ?EntityTypeRepositoryInterface $entity_type_repository = NULL, ?EntityFieldManagerInterface $entity_field_manager = NULL, EntityRepositoryInterface $entity_repository) {
     parent::__construct($entity_type_manager, $entity_type_repository, $entity_field_manager);
     $this->entityRepository = $entity_repository;
   }