diff --git a/app/views/layouts/header/_default.html.haml b/app/views/layouts/header/_default.html.haml
index 5cec443e969526ae47aff252704d770db8528766..772411fbed0fb9054067f8048a5aeab4fef3c635 100644
--- a/app/views/layouts/header/_default.html.haml
+++ b/app/views/layouts/header/_default.html.haml
@@ -61,7 +61,7 @@
           - if header_link?(:sign_in)
             %li.nav-item
               %div
-                = link_to "Sign in / Register", new_session_path(:user, redirect_to_referer: 'yes'), class: 'btn btn-sign-in'
+                = link_to "Sign in", omniauth_authorize_path(:user, :cas3), method: :post, class: 'btn btn-sign-in', "data-no-turbolink" => "true"
 
       %button.navbar-toggler.d-block.d-sm-none{ type: 'button' }
         %span.sr-only Toggle navigation