Beyoncé and Jay-Z have announced The Greenprint Project, a contest that gives fans a chance to win tickets to see both artists for the rest of their life. There’s only one catch: you need to commit to a vegan diet.

The competition is tied to Marco Borges’s new cookbook The Greenprint: Plant-Based Diet, Best Body, Better World, which Bey and Jay (who’ve been practicisng a plant-based lifestyle for a few years now) co-wrote the introduction for.

The competition doesn’t require you to go, er, cold turkey, but simply introduce elements of a plant-based diet into your life, be it meat-free Mondays or eating two plant-based meals a day. We’re not sure how anyone would actually monitor your commitment to veganism, but you wouldn’t want to lie to Beyoncé, would you?

So, if you want tickets for life (well, technically it’s actually only for 30 years, but who knows if any of us will last that long), head over to The Greenprint Project.