diff --git a/db/booking.ts b/db/booking.ts
index 7e2c21f..463a66f 100644
--- a/db/booking.ts
+++ b/db/booking.ts
@@ -64,7 +64,7 @@ BookingSchema.virtual('days').get(function () {
   return getDays({ startDate: this.startDate, endDate: this.endDate })
 })
 
-BookingSchema.static('findBookedDays', async function (): string[] {
+BookingSchema.static('findBookedDays', async function (): Promise<string[]> {
   console.log('in findBookedDays this is', this)
   const bookings = await this.find(
     {