diff --git a/backend/app/Http/Controllers/Api/FatherRelationsController.php b/backend/app/Http/Controllers/Api/FatherRelationsController.php
index c3ae5931..0d3acef3 100644
--- a/backend/app/Http/Controllers/Api/FatherRelationsController.php
+++ b/backend/app/Http/Controllers/Api/FatherRelationsController.php
@@ -47,7 +47,7 @@ class FatherRelationsController extends Controller {
     }
 
     public function updateHireDate (Request $r, $child_id) {
-        if (!isset($child_id) || !isset($r->father_id) || !isset($r->hire_at)) {
+        if (!isset($child_id) || !isset($r->father_id)) {
             return ['status_code' => 400, 'error_messages' => ['子の入社日の更新に失敗しました。']];
         }