The weekend delivered some disappointing news for laid-off Twitter employees who launched a class-action lawsuit in November against the social media platform immediately after CEO Elon Musk kicked off the first round of layoffs at the company. On Friday, a US district judge ruled that five plaintiffs who proposed the class action would instead have to enter individual arbitration to pursue their claims that Twitter violated employment laws.

This doesn’t mean the class-action lawsuit has completely fallen apart, though. US District Judge James Donato wrote in his order that while these five employees waived their right to sue by signing optional arbitration agreements under Twitter’s prior owner, three other plaintiffs later added to the lawsuit said they opted out. Those employees still have the right to pursue the proposed class action, which alleges sex and disability discrimination during layoffs and argues that Twitter still owes proper severance payments and lost wages.

“After Twitter filed its motion, plaintiffs amended their complaint to add three named plaintiffs who say that they opted out of Twitter’s arbitration agreement,” Donato wrote.

The five ex-employees dropped from the class-action suit had tried to argue that Twitter’s arbitration agreements were unreasonable, or in legal terms, “unconscionable.” But Donato wrote that the former employees failed to prove this claim, as “Twitter provided signed copies of the agreements, and they are all clear and straightforward.” The agreements specified that the question of their “enforceability and validity” could only be resolved by an arbitrator.

Twitter could not immediately be reached for comment.

Shannon Liss-Riordan, the lawyer representing the plaintiffs in individual arbitration and the ongoing class action, said last week in a press release that her firm had already filed 300 demands for arbitration on behalf of ex-Twitter employees.

Ars could not immediately reach Liss-Riordan for comment on what comes next in the class-action suit, but Donato wrote that the plaintiffs’ complaint “will be taken up later as warranted by developments in the case.”

According to Liss-Riordan’s press release, her firm has filed four class-action suits in total against Twitter and expects to continue filing many more arbitration demands—all of which, she says, could become costly for Twitter to defend against. Her firm has previously helped ex-employees recover millions through arbitration, and she’s not the only one fighting back after Twitter layoffs. Another lawyer, Lisa Bloom, is representing other former employees pursuing arbitration demands, and Reuters reported that Twitter also faces at least three complaints filed with the US labor board.

“Musk’s decision to fleece Twitter workers isn’t just shameful—it’s also going to be very costly,” Liss-Riordan said in her press release. “These claims will be extraordinarily expensive and time-consuming for Twitter to defend. Insisting that workers file claims one by one has backfired for many companies our firm has taken on. These companies think they can make employees just go away and not assert their rights by using arbitration clauses, but we have made them sorry about what they wished for.”