diff --git a/src/services/attendee/attendee-router.ts b/src/services/attendee/attendee-router.ts
index a337000..42ad60d 100644
--- a/src/services/attendee/attendee-router.ts
+++ b/src/services/attendee/attendee-router.ts
@@ -163,9 +163,7 @@ attendeeRouter.get(
             const attendeeData = AttendeeFilterValidator.parse(req.body);
             const attendees = await Database.ATTENDEE.find(
                 attendeeData.in,
-                attendeeData.out.map((x) => {
-                    x: 1;
-                })
+                attendeeData.out
             );
 
             return res.status(StatusCodes.OK).json(attendees);
diff --git a/src/services/attendee/attendee-schema.ts b/src/services/attendee/attendee-schema.ts
index ef79517..47d9d9a 100644
--- a/src/services/attendee/attendee-schema.ts
+++ b/src/services/attendee/attendee-schema.ts
@@ -95,5 +95,5 @@ export const PartialAttendeeValidator = AttendeeValidator.partial();
 
 export const AttendeeFilterValidator = z.object({
     in: PartialAttendeeValidator,
-    out: PartialAttendeeValidator.keyof().array(),
+    out: z.map(PartialAttendeeValidator.keyof(), z.number().min(0).max(1))
 });