diff --git a/src/Controller/SecurityController.php b/src/Controller/SecurityController.php
index 2d60f22..d7cf6ad 100644
--- a/src/Controller/SecurityController.php
+++ b/src/Controller/SecurityController.php
@@ -32,6 +32,7 @@ class SecurityController
             $password = $_POST['password'] ?? '';
 
             if ($nick && $password) {
+                $nick = strtolower(string: $nick);
                 if ($user = $this->userRepository->findbyNick(nick: $nick)) {
                     if (password_verify(password: $password, hash: $user->getPassword())) {
                         $_SESSION['user_id'] = $user->getId();