Beyoncé and Jay-Z fans could win free concert tickets for life if they vow to go vegan.

The couple announced the new contest as part of the Greenprint Project, which aims to improve the environment by switching to plant-based meals.

Fans do not have to go completely vegan to enter the contest. They can limit their meat intake with “Meatless Mondays” or incoprated more vegan substitutes such as “plant-based for breakfast.

Check out Beyonce’s Instagram for details:

[Billboard]