Members of three Native American tribes looking to vote in the 2018 midterms have filed suit against North Dakota’s secretary of state for allegedly suppressing their right to vote.

The complaint, filed on behalf of members of the Sioux Spirit Lake, Chippewa, and Cheyenne tribes, alleges that North Dakota’s “unplanned, untested, and broken” law requiring voters to present identification at the polls to prove their current residential address poses “a severe impediment” to their constitutional right to vote. Many Native Americans “simply have no residential address because the government has not assigned them one,” according to the lawsuit.