California became the first state to require its publicly held corporations to include women on their boards after Gov. Jerry Brown signed a bill into law on Sunday.

The bill, which applies to companies “whose principal executive offices” are in California, requires them to have at least one woman on their boards by the end of 2019.

In 2021, the companies must have a minimum of two or three women, depending on the size of their boards.

Hundreds of companies will be affected by the law, according to The Los Angeles Times, and those that fail to comply can be fined $100,000 for a first violation and $300,000 for a second.