diff --git a/.upgrade.yml b/.upgrade.yml
index d57c41765..a2fec5e91 100644
--- a/.upgrade.yml
+++ b/.upgrade.yml
@@ -1325,6 +1325,8 @@ warnings:
       replacement: 'writeJavascriptToBody'
     'SilverStripe\Forms\Formfield->dontEscape':
       message: 'FormField::$dontEscape has been removed. Escaping is now managed on a class by class basis.'
+    'SilverStripe\Security\LoginForm->authenticator_class':
+      message: 'authenticator_class is deprecated. Use getAuthenticatorClass/setAuthenticatorClass.'
     'SilverStripe\Security\Permission::$declared_permissions':
       message: 'Deprecated'
     'SilverStripe\Security\Permission::$declared_permissions_list':
@@ -1387,4 +1389,4 @@ warnings:
       url: 'https://docs.silverstripe.org/en/4/changelogs/4.4.0#resources-dir'
       replacement: 'RESOURCES_DIR'
 renameWarnings:
-  - Form
\ No newline at end of file
+  - Form