diff --git a/application/forms/Authentication/LoginForm.php b/application/forms/Authentication/LoginForm.php
index e8f053846..868302f96 100644
--- a/application/forms/Authentication/LoginForm.php
+++ b/application/forms/Authentication/LoginForm.php
@@ -16,6 +16,8 @@ use Icinga\Web\Url;
  */
 class LoginForm extends Form
 {
+    const DEFAULT_CLASSES = 'icinga-controls';
+
     /**
      * Redirect URL
      */