Following reports that he secretly had twins with one of Neuralink’s top executives, Elon Musk tweeted that he was doing his part to contribute to the Earth’s population.

Musk in the tweet said “doing my best to help the underpopulation crisis; a collapsing birth rate is the biggest danger civilization faces by far.”

Musk welcomed twins with Neuralink’s Shivon Zilis in 2021, bringing his total number of children to nine.