Burger King is offering customers its iconic Whopper hamburger for just one cent, but there’s a catch; you have to go to McDonald’s to order it.

introducing the #WhopperDetour. order a Whopper for a penny only “at” McDonald’s with the BK app. yes, you read that right, drive near a McDonald’s and use the BK app. no need to go to their drive-thru. get yours before December 12th. burgerking.app.link/i78LFkWdmS Posted by Burger King on Tuesday, December 4, 2018

In the burger chain’s latest promotion, customers who download the Burger King app, then go within 600 feet of a McDonald’s are able to order a Whopper through the app for a single penny.

The Whooper Detour is available through Dec 12.