diff --git a/partials/structure/header.php b/partials/structure/header.php
index f69393e..5c64904 100644
--- a/partials/structure/header.php
+++ b/partials/structure/header.php
@@ -126,7 +126,8 @@ if ($isLoggedIn) {
                     <button id="loginButton"
                             type="button"
                             class="relative inline-flex items-center justify-center rounded-full bg-brand-primary px-4 py-1.5 text-xs font-semibold uppercase tracking-[0.18em] text-brand-bg shadow-soft hover:bg-cyan-400 transition-colors"
-                            data-i18n="header_btn_login">
+                            data-i18n="header_btn_login"
+                            data-login-url="/login/?lang=<?= htmlspecialchars($lang ?? 'de') ?>">
                         Login
                     </button>
                 <?php else: ?>