diff --git a/server/src/routes/timeslot.ts b/server/src/routes/timeslot.ts
index 501028c..e840c8f 100644
--- a/server/src/routes/timeslot.ts
+++ b/server/src/routes/timeslot.ts
@@ -108,7 +108,7 @@ router.get("/timeslot", async (req: Request, res: Response) => {
         `, [
             new Date(timeslotFilters.startDate).toISOString(),
             new Date(timeslotFilters.endDate).toISOString(),
-            timeslotFilters.trainer !== undefined ? timeslotFilters.trainer : [1],
+            timeslotFilters.trainer !== undefined ? timeslotFilters.trainer : [],
             timeslotFilters.trainer === undefined,
             weekdays,
             timeslotFilters.center,