Gov. Mark Dayton signed a package of bills Sunday aimed at improving working conditions for women.
The Women's Economic Security Act requires businesses that contract with the state to certify they provide equal pay to men and women in the same job categories.
Businesses must also make accommodations for pregnant and nursing women.
At the bill signing, Cassondra Williams, 24, said she had to find a new job because her previous employer did not offer adequate maternity leave. Williams, a paralegal, is expecting her first child in June.
"I was offered six weeks of unpaid maternity leave. And they felt that that was generous and that was the minimum state requirement," she said.
The new law extends unpaid maternity leave from six to 12 weeks.
The Minnesota Chamber of Commerce had expressed concerns about the reporting requirements for the measure's equal pay provision, saying it could increase legal costs for businesses.