Slovakia’s parliament on Friday passed an amendment to the constitution that recognizes only two sexes, along with other measures that critics say might breach the country’s international obligations and undermine the protection of human rights.

The amended constitution now recognizes only two sexes, male and female, and states that Slovakia retains sovereignty in matters of “national identity,” which is not specifically defined, especially in “fundamental cultural-ethical questions.”

The amendment also makes it almost impossible for anyone other than married couples to adopt children. The constitution had already defined marriage as “a unique union between a man and a woman.”