thehill_Facebook is blocking pages that post fake news stories from buying ads as part of its efforts to curb hoax articles on its platform.

The company announced on Monday that it would prevent Facebook pages — public profiles for brands, celebrities, groups, businesses and other institutions — that repeatedly share news marked as “false” by third-party fact-checkers from advertising on its platform.

“This update will help to reduce the distribution of false news which will keep Pages that spread false news from making money,” wrote Facebook product managers Satwik Shukla and Tessa Lyons. “We’ve found instances of Pages using Facebook ads to build their audiences in order to distribute false news more broadly.”

The company noted that pages that stop posting fake news would be eligible to buy ads on Facebook again.In the post, the two managers reiterated Facebook’s stance that false information on the platform is “harmful” and “erodes trust.”

In December, the company announced that it would begin taking steps to curb fake stories from spreading across its platform. The move came after CEO Mark Zuckerberg initially downplayed the impact of false stories on Facebook.

“More than 99% of what people see is authentic,” Zuckerberg wrote just after the presidential election. “Only a very small amount is fake news and hoaxes.”

Facebook has since released features and tweaked its platform in a variety of ways to stop fake news from being shared on its website.

Most notably, the company introduced an option that allows users to report potentially fake stories as “false.” Third-party groups assess flagged stories to determine if they are fake. They also use algorithms to find false news stories.