Former First Lady Michelle Obama shared a photo on Twitter of her prom dress to encourage students to vote. 

“Throwing it back to my 1982 prom night and this pink satin, polka-dotted dress,” she tweeted, accompanied by a photo and a call to students to join the challenge created to raise voter turnout. “Join the #PromChallenge with When We All Vote and MTV and tell us what your school is doing to register students to vote. You could get a free prom for your school! ” 

As co-chair of When We All Vote, Obama collaborated with MTV’s +1thevote campaign to create a challenge that would “celebrate and recognize 20 high schools across the country integrating voter registration into their schools in the most creative and impactful ways.”

Students have until March 13 to submit their applications complete with their ideas on the When We All Vote website. Other notable celebrities, including Kerry Washington and Tracee Ellis Rose, have tweeted their own photos to raise awareness.