Democratic presidential candidate Bernie Sanders has chosen an unexpected campaign collaborator, announcing to CNN on Monday that he was about to link up with rapper Cardi B to film a 2020 campaign video meant to appeal to younger voters.

As he arrived at a Detroit a nail salon for the video shoot with Cardi B, the independent senator from Vermont told CNN that the younger generation’s political participation is vital to the nation’s future. “They are voting in large numbers, but not large enough numbers.”

He told CNN that he and the singer had talked about student debt, climate change and other campaign issues before filming at TEN Nail Bar.

Cardi B later thanked the senator in an Instagram post, saying she looked forward to seeing how he would fight for “economic, racial and social justice for all.”

Weeks earlier, she said, she had asked her followers to submit questions they’d like to ask a Democratic candidate, and she selected the most popular to bring to Sanders.

“Together, let’s build a movement of young people to transform this country,” she wrote, encouraging her followers in that post and others to learn about the candidates and to support Democrats.