The United States Senate has voted to allow the babies of its members into the tradition-bound chamber.

The inspiration for the historic change of rules was Sen. Tammy Duckworth’s daughter, born April 9. Duckworth wants to resume voting, and the Senate requires that votes be cast in person.

So the Illinois Democrat, now on maternity leave, proposed that babies be allowed into the chamber. She says the vote Wednesday helps “bring the Senate into the 21st Century.”