A United States federal appeals court on Friday reinstated part of a lawsuit accusing Elon Musk’s social media platform, X (formerly Twitter), of fostering an environment that allowed child exploitation content to thrive.

While the court upheld broad legal protections for the platform under Section 230 of the Communications Decency Act, it ruled that X must face a negligence claim for failing to promptly report explicit content involving minors.

The case, which predates Musk’s 2022 acquisition of Twitter, was originally dismissed in December 2023 by a lower court. The 9th U.S. Circuit Court of Appeals in San Francisco, however, determined that X could be held accountable for not immediately reporting a video containing child sexual abuse material to the National Center for Missing and Exploited Children.

According to court filings, the video, which included explicit images of two underage boys, remained online for nine days after X was notified and amassed more than 167,000 views before being removed and reported.

Circuit Judge Danielle Forrest, writing for the three-judge panel, said Section 230 immunity did not apply once the platform had actual knowledge of the illegal content. “The facts alleged here, coupled with the statutory ‘actual knowledge’ requirement, separate the duty to report child pornography to NCMEC from Twitter’s role as a publisher,” she wrote.

The plaintiffs, identified as John Doe 1 and John Doe 2, were reportedly coerced via Snapchat into sending nude images, which were later compiled and shared on Twitter by a child pornography trafficker.

While the court dismissed claims that X benefited from sex trafficking or intentionally amplified such content, it allowed another claim to proceed—that X’s platform design made it unreasonably difficult for users to report child sexual abuse material.

X and Musk have not publicly commented on the ruling. The case now heads to trial.