OMAHA, Neb. (AP) — Seven same-sex couples have filed a lawsuit to have their marriages recognized in Nebraska.

The American Civil Liberties Union of Nebraska announced Monday that the couples have challenged the state’s constitutional ban on marriage in federal court.

ACLU of Nebraska Executive Director Danielle Conrad says it’s time for the state to extend the freedom to marry to all of its citizens.

The plaintiffs include Susan and Sally Waters of Omaha, who have been together for 17 years. Sally Waters was diagnosed with terminal breast cancer last year. She says without formal recognition of their marriage in Nebraska, her spouse won’t receive the same tax and Social Security benefits to take care of the couple’s children.

Top state officials have said they will fight the lawsuit.