Employers lost one legal pathway to eliminating job bias suits in federal court in a unanimous decision by the U.S. Supreme Court on Monday.

The high court, led by Justice Ruth Bader Ginsburg, ruled that the requirement that a worker first file a discrimination charge with the Equal Employment Opportunity Commission as a precondition to filing a Title VII lawsuit is not a jurisdictional requirement but a mandatory claims-processing rule. And an employer must timely raise a worker’s failure to file a charge or forfeit that defense.

Ginsburg, in an 11-page opinion, rejected arguments by Texas’ Fort Bend County that the charge-filing precondition under Title VII of the Civil Rights Act of 1964 was a jurisdictional requirement that goes to a court’s authority to hear a suit and that can be raised at any stage of a proceeding.

“Like kindred provisions directing parties to raise objections in agency rulemaking, follow procedures governing copyright registration, or attempt settlement, Title VII’s charge-filing requirement is a processing rule, albeit a mandatory one, not a jurisdictional prescription delineating the adjudicatory authority of courts,” Ginsburg wrote.

The high court case—Fort Bend County v. Davis—stemmed from a charge against the county by Lois Davis, who alleged sexual harassment and retaliation for reporting the harassment. While that charge was pending with the Equal Employment Opportunity Commission, Davis was fired for refusing to work on a Sunday; she went to a church event instead. Davis amended her EEOC intake questionnaire to include “religion,” but she did not amend the formal charge document.

After years of litigation, only the religious discrimination claim remained in her lawsuit. Fort Bend then asserted that the court lacked jurisdiction to decide the case because her charge did not include a religious discrimination claim. The district court agreed, but the U.S. Court of Appeals for the Fifth Circuit reversed. The appellate court ruled that the charge-filing requirement was not jurisdictional but a “prudential prerequisite” to filing suit. Fort Bend forfeited the defense, said the court, because it didn’t raise it until after “an entire round of appeals all the way to the Supreme Court.”

The U.S. Chamber of Commerce and other business groups supported Fort Bend, saying in an amicus brief that a ruling against the county would result in charging parties having “less incentive to craft thoughtful and complete administrative charges, leading to critical omissions resulting in unfair surprise to their employers months, or even years, after the alleged incidents occurred.”

But Ginsburg dismissed those concerns, writing that “recognizing that the charge-filing requirement is nonjurisdictional gives plaintiffs scant incentive to skirt the instruction. Defendants, after all, have good reason promptly to raise an objection that may rid them of the lawsuit filed against them. A Title VII complainant would be foolhardy consciously to take the risk that the employer would forgo a potentially dispositive defense.”

The decision was a unanimous win for Raffi Melkonian, a partner at Wright Close & Barger in Houston, in his first argument before the high court. Melkonian, who coined the #AppellateTwitter handle, unsurprisingly took to Twitter within minutes of the posting of the opinion.

“That is one killer birthday present, Justice Ginsburg! Thank you!” Melkonian exclaimed. “In all seriousness, we are delighted and we look forward to delivering justice for Ms. Davis in front of a Texas jury.”

The U.S. Justice Department supported Davis in the high court as did the Constitutional Accountability Center and the National Employment Lawyers Association.

“While this case may have flown under the radar, it is nonetheless important: because of the Court’s decision today, Lois Davis, who sued her employer for religious and sex-based discrimination and retaliation, will be able to have her day in court,” said the center’s chief counsel, Brianne Gorod, in a statement.

Hogan Lovells’ partner Colleen Roh Sinzdak represented Fort Bend. Assistant to the Solicitor General Jonathan Bond argued on behalf of the United States.