Trump voters are about to find out which of their Facebook friends are the product of a Russian troll farm.

The social network revealed Thursday it is creating “a portal to enable people on Facebook to learn which of the Internet Research Agency Facebook Pages or Instagram accounts they may have liked or followed between January 2015 and August 2017.”

The Internet Research Agency, an infamous St. Petersburg-based troll farm with links to the Kremlin, has been blamed for much of the government-backed disinformation campaign designed to disrupt the 2016 election.

The initiative is part of Facebook’s continuing effort to be more transparent about the network’s infiltration by fake Russian accounts; the network admitted content from fake Russian accounts could have reached as many as 126 million people over the two-year period, and a further 20 million on Instagram.

Facebook, along with Google and Twitter, faced Congress earlier this month to answer questions about how the infiltration happened and what steps are being taken to remove it.

In a meeting on the sidelines of the Asia-Pacific Economic Cooperation summit in Vietnam earlier this month, Russian President Vladimir Putin denied meddling in the U.S. vote. Trump said he believed him.

“He did not do what they are saying he did,” Trump told reporters on Air Force One.

Facebook has said it is trying to be more transparent about who is buying ads on its network, but a report by ProPublica this week showed it still has major issues.

The report disputes Facebook’s claim that it had built a system to spot and reject ads that discriminated based on race.

ProPublica said it bought dozens of rental housing ads on Facebook last week but was still able to ask that they not be shown to certain categories of users, such as African Americans, mothers of high school kids, people interested in wheelchair ramps, Jews, expats from Argentina and Spanish speakers.