INDIANAPOLIS (AP) — Indiana’s state parks are offering campers a 20 percent discount on weeknight camping through Nov. 4.

The Indiana Department of Natural Resources announced the deal Monday. It’s available for those who book a new campsite or cabin on a Sunday through Wednesday. The offer applies to Indiana State Parks, state park-managed lake campgrounds, Deam Lake and Starve Hollow state recreation areas and Greene-Sullivan State Forest.

State officials say the deal doesn’t apply to walk-in registrations and doesn’t apply to Thursday, Friday or Saturday nights. The promo code for online or phone orders is INFALL15.

Reservations must be used and booked by Nov. 4.