The Democratic National Committee has sued the Trump administration over changes to the voter registration form used by US citizens living abroad.

The lawsuit, filed Thursday, says the Pentagon removed a box on the Federal Post Card Application for citizens who have never lived in the United States. The change was made in August through two emergency requests approved by the Office of Management and Budget, according to reports.

Thirty-eight states and the District of Columbia allow citizens born abroad to vote in at least some elections. About 11,500 such voters cast ballots in 2016, and the number has likely grown.

The DNC says the change violates the Administrative Procedure Act and calls the emergency manufactured. It asks a federal court in Washington to block the altered form.

The Pentagon did not respond to requests for comment. NPR first reported the changes earlier this week.

Voting experts warn the removal could confuse eligible voters and discourage them from registering ahead of the midterms.