In a statement shared on Twitter Tuesday, the online language learning company acknowledged placing an ad “with Fox.” But the company said it “did not know” the ad would air during the prime time “Tucker Carlson Tonight” program, which it called “so repugnant and at odds with our mission and values.”

Language-instruction app Babbel said it was “deeply sorry” after one of its ads was broadcast this week during an episode of Tucker Carlson’s controversial Fox News show.

If you saw our ad on Tucker Carlson’s show, you’re right to be upset. We are too. While we did place our ad with Fox, we did not know it would air on a show so repugnant and at odds with our mission and values. We are blacklisting the show going forward. We are deeply sorry.

Carlson, who has a history of repeating white nationalist talking points, sparked outrage in December when he claimed on air that immigrants were making the U.S. “poorer and dirtier and more divided.” Numerous companies, including Pacific Life, IHOP, Bowflex and Ancestry.com, pulled their advertisements in response.

Carlson faced another advertiser backlash in March following the resurfacing of previous radio show recordings in which he made sexist, homophobic, racist and misogynistic comments, including a sexually explicit joke about a Miss Teen USA contestant.

Not all advertisers decided to cut ties with the show, however, which Deadline reported was the second most-watched cable news program in April with more than 2.8 million viewers.

It’s not clear whether Babbel has pulled its ads from all Fox shows.

Fox News pushed back on Babbel’s comments in a statement from a spokesperson: