Though Vincent Price was typically a constant professional on film sets, he was only human. As we all known, every once in a while, humans are prone to laughing at inopportune times.

Price’s daughter explained one experience where one of her father’s horror films became the source of a great deal of laughter.

In her book, Vincent Price: A Daughter’s Biography, Victoria Price recalled her father’s 1958 film, The Fly. Based off of a story by George Langelaan, Victoria said that the film was “destined to become a late-night TV staple and a cult classic.”

In the film, Price played François Delambre, brother to scientist André Delambre. Victoria revealed that while filming on of the more climactic scenes, Price and his co-star, Herbert Marshall, couldn’t stop laughing.

“In the film’s famous final scene, the fly, complete with a miniature human head, screams ‘Helllp meee!” over and over again until finally heard by Price and Marshall,” wrote Victoria Price. “While filming the scene, neither actor was able to maintain a straight face; according to Vincent, the more they tried to regain their professional composure, the more ludicrous the whole thing seemed, and they dissolved into helpless giggles. Each successive take only made it worse, until both men were sitting on the ground with tears of laughter streaming down their faces. Nobody knows exactly how many takes director Kurt Neumann required to finally get it right.”

According to Mark A. Vieira’s book, Hollywood Horror: From Gothic to Cosmic, Price was particularly tickled by the tiny voice, ostensibly coming from his fictional brother. “We could never get the lines out,” said Price. “because every time that little voice of the fly would say, ‘Help me. Please help me,’ we would just scream with laughter! It was terrible.”