Bud Abbott and Lou Costello’s famous “Who’s On First?” sketch has become such a part of American comedy that it has been copied everywhere. It’s now being played on stage once again in Hand To God, the Tony-nominated play about a Texas teen and his sock puppets.

The famous comedy team’s heirs caught wind of the sketch’s use and have filed a lawsuit against the show’s producers in Manhattan federal court this week. According to The Hollywood Reporter, the plaintiffs are TCA Television Corporation, which is owned by Costello’s heirs; Hi Neighbor, owned by Abbott’s; and Diana Colton, another Abbott heir.

In the play, the main character, Jason, tries to impress a girl, Jessica, by performing the sketch with his hand puppets, notes The New York Post. At first, he says he created the sketch himself - which the audience knows isn’t true - but later admits that it was an old routine.

Rick Miramontez, a play spokesman, said that producer Kevin McCollum made sure that there would be no legal issues with the script. He added that the sketch is in public domain and suspected that the suit was nothing more than a publicity stunt on the eve of the Tonys, which are Sunday.

Abbott & Costello first performed their famous sketch on the radio in 1938 and recreated in Universal films and on television. Here’s one version of it: