diff --git a/src/TimeBasedFieldUpdater.php b/src/TimeBasedFieldUpdater.php
index 9aede03..bfac54f 100644
--- a/src/TimeBasedFieldUpdater.php
+++ b/src/TimeBasedFieldUpdater.php
@@ -35,7 +35,7 @@ final class TimeBasedFieldUpdater {
             $this->updateEntity($id, $new_values);
         }
     }
-    private function updateEntity(int $entity_id, array $new_values): void {
+    private function updateEntity(string $entity_id, array $new_values): void {
         $entity = $this->entityTypeManager->getStorage($this->entity_type)->load($entity_id);
         foreach($new_values as $new_field=>$new_value) {
             $entity->$new_field = $new_value;