CHICAGO (CBS)–The Burger King vs. McDonald’s rivalry just escalated to a whole new level, thanks to an offer Burger King announced Tuesday selling 1 cent Whoppers–with a catch.

In order to get the #WhopperDetour deal, customers have to be at a McDonald’s while using the Burger King app.

App users can get the deal through Dec. 12 by following four steps, explained in a YouTube video posted by Burger King:

1.) Download the Burger King app

2.) Drive within 600 feet of a McDonald’s

3.) Order a Whopper on the app

4.) Drive to the nearest Burger King to pick up the order

In a tweet, Burger King says there’s no need to actually go through the McDonald’s drive-thru because the deal unlocks when the app is used nearby any McDonald’s location.

“We would never tell you to go to McDonald’s. Or would we?” Reads a Burger King post on YouTube for the  #WhopperDetour.