diff --git a/src/EventListener/Backend/DataContainer/ModuleListener.php b/src/EventListener/Backend/DataContainer/ModuleListener.php
index 7a7eb1e..c8b4138 100644
--- a/src/EventListener/Backend/DataContainer/ModuleListener.php
+++ b/src/EventListener/Backend/DataContainer/ModuleListener.php
@@ -103,6 +103,7 @@ private function handlePersonalDataModule(): void
     private function handleNewsletterSubscribeModule(): void
     {
         $GLOBALS['TL_DCA']['tl_module']['palettes']['newsletterSubscribeNotificationCenter'] = $GLOBALS['TL_DCA']['tl_module']['palettes']['subscribe'];
+        $GLOBALS['TL_DCA']['tl_module']['fields']['nc_notification']['eval']['mandatory'] = true;
 
         PaletteManipulator::create()
             ->addField('nc_notification', 'email_legend', PaletteManipulator::POSITION_APPEND)