BOSTON – Republican Gov. Charlie Baker has signed into law a bill requiring men and women be paid equally for comparable work in Massachusetts.

Baker signed the bill during a Statehouse ceremony Monday.

Women are currently paid on average about 82 percent of what their male counterparts make for comparable work in Massachusetts.

In what backers say is a first-in-the-nation provision, the new law bars employers from asking prospective workers to provide a salary history. Supporters say that practice can perpetuate a cycle of lower salaries for women. Prospective employees could voluntarily offer salary information.

The law also lets employees discuss their salaries with other workers without facing retribution from their employer.

The new law takes effect July 1, 2018.