diff --git a/src/User/FlatFileUserRepository.php b/src/User/FlatFileUserRepository.php
index 9c20fdb..73e89ce 100644
--- a/src/User/FlatFileUserRepository.php
+++ b/src/User/FlatFileUserRepository.php
@@ -22,6 +22,7 @@ class FlatFileUserRepository implements UserRepository
                 return new User($user['email'], $user['password']);
             }
         }
+        return null;
     }
 
     public function save(User $user): User