Sheryl Sandberg says Facebook really means it this time.

Last year, Facebook was found to have allowed housing advertisers to exclude targets based on race and "ethnic affinity." The social network said it would make changes. Last week, Facebook was found to still be allowing the practice with rental ads, according to ProPublica, which reported on the issue in the first place.

Now Facebook's chief operating officer says the company is suspending advertisers' ability to possibly violate the Fair Housing Act, as critics of the ad tools have charged.

"Until we can better ensure that our tools will not be used inappropriately, we are disabling the option that permits advertisers to exclude multicultural affinity segments from the audience for their ads," Sandberg wrote in a letter to Congressional Black Caucus Chairman Cedric Richmond dated Wednesday.

Sandberg met with the CBC last month in Washington, where black lawmakers shared their concerns about such things as the lack of diversity on Facebook's board and how the perception of the Black Lives Matter movement is affected by the world's largest social network.

In Wednesday's letter, Sandberg addressed those concerns, and announced the suspension of the ad tools that allowed exclusions based on race and ethnicity. She said Facebook has been working with Rep. Robin Kelly, D-Ill., a Congressional Black Caucus member, and other civil rights and advocacy organizations on examining the problem.

"When I first raised this issue with Facebook, I was disappointed," Kelly said in a statement, according to Fortune. "When it became necessary to raise the issue again, I was irritated. Thankfully, we've been able to establish a constructive pipeline of communication that's resulted in a positive step forward."

While Sandberg in the letter defended "multicultural marketing" as a "common practice in the ad industry," she said "we will also conduct a full review of how exclusion targeting is being used across audience segments."

Facebook also has allowed the ability to target "Jew haters," ProPublica reported in September. Sandberg told the Congressional Black Caucus that when it comes to ad review, "we rely on both automated and manual review, and we're taking aggressive steps to strengthen both."