Prepare to meet Mr. Hofstadter.

After 9 seasons, The Big Bang Theory has finally cast Leonard’s (Johnny Galecki) father. According to The Hollywood Reporter, Taxi alum Judd Hirsch will be playing the patriarch of our nerdy protagonist. Hirsch will appear in the May 12 finale of the CBS comedy.

Galecki surprisingly played a huge part in casting his father. He told The Hollywood Reporter at the February 21 tribute to veteran sitcom director James Burrows about his first encounter with Hirsch, and the parallels between Hirsch’s character Alex on Taxi and Leonard. “I ran up to him and bombarded him with conversation that went on for a long time about what a fan I am. I did share with him that when we were shooting the pilot, I re-watched the first two or three seasons of Taxi — not because I wanted to base Leonard on his character but the purpose his character served, this anchor in this group of people — and he was just as much at times a voice of reason as he was just as confused as everyone else. I shared that with him, and a lightning bolt struck … or another merlot … and I said, ‘Would you have any interest in playing my dad on the show?'”

Added Simon Helberg who plays Howard- “And he said, ‘No, but Rhea Pearlman is available.'”

Taxi ran for five season from 1978- 1983. It’s one of the seminal American sitcoms, so it’s fitting that its star is now playing a father in the current embodiment of the American sitcom. Hirsch was nominated for Outstanding Lead Actor in a Comedy Series Emmy every season  of Taxi and won twice.

Other sitcom veterans have played the Big Bang cast’s parents over the seasons.  Years after playing manic sister Jackie on Rosanne, Laurie Metcalf has played Sheldon’s (Jim Parsons) extremely religious but caring mother. Several seasons ago we met Bernadette’s (Melissa Rauch) tough and taciturn father in the form of Grace Under Fire’s Casey Sander (another Chuck Lorre production). Most notably,  Cybill star (Chuck Lorre strikes again) Christine Baranski has won an Emmy for her turn as Leonard’s incredibly cold mother Dr. Hofstadter.

Despite being in its ninth season, The Big Bang Theory is still going strong, averaging over 20 million viewers per episode.