South Africa’s Constitutional Court has struck down a law that barred men from automatically assuming their wives’ surnames, declaring it unconstitutional and a violation of gender equality.

In its judgment on Thursday, the apex court nullified a section of the Births and Deaths Registration Act, which required men to apply for official approval to change their names, while women could adopt their husbands’ surnames automatically after marriage, divorce, or widowhood.

“The court found that the inability of men to assume their wives’ surnames constitutes differentiation,” the court said in a post on social media. It ruled that the law amounted to unfair gender discrimination, depriving men of equal rights and reinforcing patriarchal norms.

The case was brought forward by two couples: Jana Jordaan and Henry Van Der Merwe, and Jess Donnelly-Bornman and Andreas Nicolas Bornman. Van Der Merwe testified that he was denied the right to take his wife’s surname, while Bornman said he was refused permission to hyphenate his name with his wife’s.

The couples first challenged the law in a High Court, which agreed that the section was unconstitutional. However, the Constitutional Court’s confirmation was required for the ruling to take effect nationwide.

In its detailed findings, the Constitutional Court noted that the law entrenched outdated cultural expectations. “It reinforces patriarchal gender norms, which prescribe how women may express their identity, and it makes this expression relational to their husband, as a governmental and cultural default,” the court said.

The ruling has been hailed as a milestone for gender equality in South Africa, placing men and women on the same legal footing in matters of family identity. Women now also have the right to see their surnames recognized as family names if their husbands choose to adopt them.