We love hearing stories from the vault.

Jack Black recently joined David Spade and Dana Carvey’s “Fly on the Wall” podcast on Wednesday. During the episode, he discussed the advice given to him by “SNL” creator Lorne Michaels when he hosted the show the prior month.

“Lorne said the funniest thing. I don’t think he was trying to be funny,” the actor, 55, explained. “After the rehearsal, when he saw me do the tiger roll and he saw me doing that rockin’ number, and he saw me sweating and wheezing, he said, ‘I just want to tell you a story.’ ”

“In the ‘70s, this is the beginning, we had Desi Arnaz on the show,” Michaels, 80, told Black. “And he was getting up there, he was in his 70s. And I wanted him on, because I just thought, yes he’s older, but he’s an icon.”

Arnaz hosted season one episode 14 on February 21, 1976, but Black recounted that the creator told him that “Desi was kind of struggling.”

Arnaz, who was married to Lucille Ball from 1940 to 1960, wanted to perform his “Babalú” number, which was his signature performance for his character Ricky Ricardo from “I Love Lucy.” 

The Babalú saw Arnaz singing while playing the drums with a band behind him. The piece originated on the sitcom — which ran for six seasons from 1951 to 1957 — but Arnaz continued to do it long after the series ended.

“Lorne was a little worried about it. Can he still pull it off?” Black told Carvey, 69, and Spade, 60. “And he was doing it, but he could see that he was starting to sweat and really struggle physically while he was ‘Babalú’-ing and he wouldn’t stop.”

“Then he looked closer on the screen and he’s like, ‘Desi’s lips started to turn blue’ and he started to worry like, ‘Oh, he’s about to die,’ ” he continued. “And he just pulled the plug on it and said, ‘Just go to commercial, whatever.’ “

Black didn’t know what to make of Michaels’ remarks, sharing, “I was like, ‘Wait a second, are you telling me this story because you’re worried I’m going to die [appearing on ‘SNL’]?’ 

“Lorne was a little worried,” admitted Black. “He was just warning me not to go too hard. Because if I went full hard as a motherf–ker, that I could die.”

The “Goosebumps” actor is no stranger to Studio 8H, as he has hosted “Saturday Night Live” in 2002, 2003, 2005 and again this year.

In April, Black got candid on returning to the show after two decades, alongside musical guests Elton John and Brandi Carlile.

Prior to the night, the “Minecraft” star called his appearance on “SNL” “cray cray” while talking to Variety.

Black added that he was feeling the pressure.

“​​Just so you know, having lots of nightmares and night terrors and also fond memories flooding back. It’s crazy, very exciting,” teased Black.

“You know what they’re thinking about right now? They are just all in a dead coma from last night’s show,” the star said of the cast and writers. “Maybe some of them are thinking of some ideas, but I’m really thinking it’s one of those shows they put together in one week, that’s part of the excitement.”

Black said he loves “all those kids” currently on Season 50.

“I call them kids because I was on that show before some of them were born — except for Kenan [Thompson], we’re around the same age. That’s about it,” he confessed.

Michaels created the sketch comedy show on Oct. 11, 1975. A variety of A-listers got their star on the series, including Jimmy Fallon, Amy Poehler, Mike Myers, Chevy Chase, Will Ferrell and Tina Fey.