Editor’s Note: Gov. Jerry Brown announced Sept. 30 that he signed Senate Bill 826 into law.

California is poised to become the first state to mandate that public companies have at least one woman on their boards of directors.

The state Senate passed the measure 23–9 on Thursday, one day after the Assembly approved it 41–26. If Gov. Jerry Brown (D) signs it into law, the one-woman rule would be in play by the end of 2019.

Within two years, the mandate, which is opposed by business groups, would increase to dictating at least two women on boards with five directors and at least three women for six-director boards.

Companies that don’t comply would be fined — $100,000 for a first violation and $300,000 for subsequent infractions. Companies that don’t inform the state about their board make-ups would face $100,000 fines.

Opponents say the bill violates constitutional law, discriminates against men and could lead to legal challenges.

The bill’s sponsor, Sen. Hannah-Beth Jackson (D–Santa Barbara) said other countries have set precedent. Germany, for example, stipulates that company boards must have 30% female representation, whereas France and Norway put the threshold at 40% for some companies.

Jackson said that one-fourth of California’s public companies currently do not have a single female on their board.