Starting Thursday, Canadians will have a new way to identify their sex on passports and other government documents: “X” will join the options of male and female.

The decision to allow the third category, indicating an “unspecified” sex, is intended to protect the rights of Canadians to identify by the gender of their choice, the country’s immigration department said in announcing the change. Ahmed Hussen, the minister of immigration, refugees and citizenship, said in a statement that the designation was added to advance “equality for all Canadians regardless of gender identity or expression.”.

The move is part of a broader push to embrace nontraditional forms of gender expression. In November, Prime Minister Justin Trudeau appointed a special adviser to coordinate government efforts to promote equality for lesbian, gay, bisexual and transgender individuals. A law passed in June amended the Human Rights Act to include nondiscrimination protections for gender identity and gender expression.