By Esther Zuckerman
September 09, 2014 at 01:59 PM EDT
Paul Archuleta/FilmMagic

Mel Brooks added a little something extra to his handprint when he preserved it in cement for the Los Angeles’s famed TCL Chinese Theatre yesterday: an 11th finger. The comedian wore a prosthetic finger on his left hand for his ceremony, giving future tourists a reason to double-take. (We can only imagine how Lucy would have reacted.) Brooks slyly tweeted about his joke:

I desperately need to wash my hands.

— Mel Brooks (@MelBrooks) September 8, 2014

Later, the 88-year-old explained the thought process behind his gag when he appeared on Conan. “I wanted to do something just a little different, I didn’t know what,” he said. “So I got another finger.” O’Brien erupted in laughter as Brooks held up his hand for the audience: “Look at that! That is so realistic.”

Brooks’ classic Young Frankenstein is celebrating its 40th anniversary this year.