Discrimination against natural and protective Black hairstyles is now banned in Massachusetts, thanks in part to two sisters who started advocating for such a law after they were punished by their Malden charter school for the way they wore their hair in 2017.

One of the sisters, Mya Cook, said on Greater Boston that she cried in school the day she was told to change her hairstyle. "I felt embarrassed. I felt shame. I just felt, like, dirty," she said.

The Cook sisters spoke out, and Mya, now 21 years old, said it felt "amazing" to see Gov. Charlie Baker sign a bill this week banning discrimination against natural hairstyles. Massachusetts is the 18th state to pass a version of what's known as the Creating a Respectful and Open World for Natural hair, or CROWN, Act.

"I knew I wasn't going to stand for what was happening and also it also helped having my sister there too, we both knew we weren't going to accept the treatment we were getting from our school administration," Cook said, adding that she and her sister Deanna won't stop advocating for the CROWN Act until it is federal law.

Rep. Brandy Fluker Oakley, a co-sponsor of the bill, said she has taken "painstaking" measures over the years to straighten her hair. She said the law "puts folks on notice that we are not going to tolerate overt discrimination."

WATCH: Hairstyle discrimination ban thanks to the CROWN Act and Malden sisters