The Department of Justice has filed a brief arguing that the Civil Rights Act of 1964, which bans discrimination on the basis of sex, doesn't apply to "homosexuals."

The amicus brief, filed with a federal court of appeals on Wednesday night, argues that Title VII of the Civil Rights Act only applies to men and women are treated unequally.

"The essential element of sex discrimination under Title VII is that employees of one sex must be treated worse than similarly situated employees of the other sex," it reads, "and sexual orientation discrimination simply does not have that effect."

Understandably, it sparked outrage among LGBT organizations and advocates.

The brief was filed in response to Zarda v. Altitude Express, a suit filed by Donald Zarda, a skydiving instructor who alleges his employer, Altitude Express, violated the Civil Rights Act when they fired him after he disclosed his sexuality to a client.

Zarda's case was rejected before he died in 2014, but an appeal was later filed on behalf of his estate.

It's unusual for the Justice Department to weigh in on private employment lawsuits, but if Zarda's estate was to win it would set a precedent for including sexual orientation under Title VII protections.

It's also unusual, at least in the 21st century, for a federal agency to use the word "homosexuals" to refer to members of the gay community. The word, which shows up at least 7 times in the DOJ's brief to refer to gay men and lesbians, is often perceived as a dog whistle for homophobes.

In 2015, a federal judge ruled that "claims of sexual orientation discrimination are gender stereotype or sex discrimination claims," in a Title IX case, but debates over the scope of Title VII have been playing out in federal courts for years. Several other federal cases brought on the basis of sexual orientation discrimination under Title VII have failed.

The U.S. Equal Employment Opportunity Commission (EEOC), however, holds the official position that Title VII does apply to sexual orientation.

The purpose of the EEOC is to determine the application of the equal rights law, but DOJ lawyers under Attorney General Jeff Sessions argue in their brief that "the EEOC is not speaking for the United States and its position about the scope of Title VII is entitled to no deference beyond its power to persuade." They add that, "Any efforts to amend Title VII’s scope should be directed to Congress rather than the courts."

The DOJ's brief comes just one day after Donald Trump announced that transgender people are banned from serving in the military.