diff --git a/lib/Notifications/ExAppNotifier.php b/lib/Notifications/ExAppNotifier.php
index ac25b023..34e237de 100644
--- a/lib/Notifications/ExAppNotifier.php
+++ b/lib/Notifications/ExAppNotifier.php
@@ -36,6 +36,9 @@ public function getName(): string {
 	}
 
 	public function prepare(INotification $notification, string $languageCode): INotification {
+		if (empty($this->service->getExAppsList())) {
+			throw new UnknownNotificationException();
+		}
 		$exApp = $this->service->getExApp($notification->getApp());
 		if ($exApp === null) {
 			throw new UnknownNotificationException();