diff --git a/app/Http/Controllers/UserController.php b/app/Http/Controllers/UserController.php
index 9b991fc2..8bf834d8 100644
--- a/app/Http/Controllers/UserController.php
+++ b/app/Http/Controllers/UserController.php
@@ -92,6 +92,8 @@ class UserController extends Controller
         $user = Auth::user();
         if ($user->canSign()) {
             $acquiredScore = $user->sign();
+            $user->last_sign_at = get_datetime_string();
+            $user->save();
 
             return json([
                 'errno'          => 0,