Burger King is offering one-cent Whoppers when you’re “at” McDonald’s during their “Whopper Detour” campaign.

According to the restaurant chain, if you download the Burger King mobile app on your phone and drive to a McDonald’s store, you can get the discount from Tuesday until December 12, 2018.

They say “at McDonald’s” means within 600 feet of one — no, McDonald’s isn’t going to service you a Burger King sandwich.

Once you're on the app, you’ll be able to order a one-cent Whopper and pick it up at the nearest participating Burger King location.