diff --git a/frontend/src/routes/aktivitaeten/+page.server.ts b/frontend/src/routes/aktivitaeten/+page.server.ts
index aacab562..8d5e3fb1 100644
--- a/frontend/src/routes/aktivitaeten/+page.server.ts
+++ b/frontend/src/routes/aktivitaeten/+page.server.ts
@@ -71,8 +71,9 @@ export async function load({ fetch, url }) {
 export const actions = {
 	'dismiss-notification': async ({ request, fetch }) => {
 		const data = await request.formData();
-		const notificationId = data.get('notificationId') as string | null;
-		if (!notificationId) return fail(400, { error: 'Ungültige Benachrichtigungs-ID' });
+		const raw = data.get('notificationId');
+		const notificationId = typeof raw === 'string' ? raw : null;
+		if (!notificationId) return fail(400, { error: null });
 		const api = createApiClient(fetch);
 		const result = await api.PATCH('/api/notifications/{id}/read', {
 			params: { path: { id: notificationId } }