He clapped back — with a lawsuit.

Former Assemblyman Dov Hikind sued Rep. Alexandria Ocasio-Cortez on Tuesday for blocking him on Twitter.

Hikind claims in a lawsuit filed in Brooklyn federal court that the freshman congresswoman prevented him from viewing her account because of “opinions he expressed” about her in replies on the social media site.

“Because of Plaintiff’s criticisms of AOC, Mr. Hikind has been prevented or impeded from viewing AOC’s tweets, from replying to the tweets, from viewing discussions associated with the tweets, and from participating in those discussions,” the lawsuit reads.

In the suit, Hikind cites a court ruling against President Trump.

A federal appeals court in New York ruled on Tuesday that Trump’s practice of blocking critics on Twitter runs afoul of the First Amendment.

The @AOC account has more than 4.6 million followers and regularly posts witty retorts to her detractors.

Some have collected lists of her most infamous “clapbacks.”

Hikind, a former Democratic lawmaker from Brooklyn, added that “several others, including journalists” have been blocked from viewing or interacting with Ocasio-Cortez’s tweets.

“If you or anyone you know has been blocked by @AOC please get in touch with me ASAP!” Hikind tweeted on Tuesday.