(CNN) -- Burger King is trolling its biggest rival with a promotion available through the Burger King Mobile App.
All you have to do is get within about 600 feet of a McDonald's and use Burger King's BK App to order a Whopper. Courtesy: Burger King / CNN
For a limited time, you can order Whopper for a penny, but you can only do it at McDonald's.
It's actually pretty simple.
All you have to do is get within about 600 feet of a McDonald's and use Burger King's BK App to order a Whopper.
Then, just drive to the nearest Burger King and pick up your sandwich -- at the cost of a single penny.
The promotion is called the "Whopper Detour" and runs Tuesday through December 12th.
Burger King launched the promotion with a video showing people trying to pick up their Whoppers at McDonald's drive-through windows.