Zac Efron’s ‘Iron Claw’ co-star sang ‘High School Musical’ on set

They were soarin’, flyin’.

Former Disney star Zac Efron revealed in a new interview that his “The Iron Claw” co-star poked fun at him by belting out a “High School Musical” song on set.

“I sung [some of ‘Breaking Free’] to Zac when I was playing my music scene. That was definitely a life experience that I’ll never forget,” Stanley Simons told People during a live Q&A event. “When I was singing the song, he was like, ‘Oh, you’re not hitting it, you’re not hitting it.’ I was like, ‘Oh,’ and I redid it. And I think I did a good job!”

Efron, 36, later chimed in, calling the moment one of “the most fun days.”

“God damn it, Stanley! I do remember that being one of the most fun days that we had,” Efron said. “Filming a house party could go one way or the other. It’s a lot of people that are stuck in one room for many days, it can be kind of daunting. But this one was just electric. It felt like a high school party.”

“We really bonded and got to hang out,” Simons interjected. “When we got on set it just felt natural. They were really welcoming to me, not just my brothers but all the cast members. So it was a little nerve-racking, but they just were very open.”

The film — which recently premiered in Dallas — tells the true story of the Von Erich brothers who were enshrined in wrestling history in the 1980s as they attempted to cope with a series of personal tragedies from 1959 to 1993, which are now referred to as the “Von Erich curse.”

“I started intermittent fasting just after I stopped being vegan,” Efron told Men’s Health. “My body wasn’t processing the vegetables in the right way.”

“So, I decided to stop it and try something new,” he added. “Intermittent fasting has been really helpful with that.”

According to Efron’s co-star Jeremy Allen White, the “17 Again” star was “a maniac” when it came to preparing for the role.

“He’s so focused and knowledgeable on training, diet, all that. In terms of a physical transformation, I think he kind of blew us all out of the water,” White, 32, told Esquire in May. “He looks really amazing in this thing.”

Off-screen, however, Efron has been subject to heavy scrutiny after some critics claimed that he looked “unrecognizable” in a promotional Entertainment Weekly interview.

“He’s looking like a Minecraft character,” one user wrote on Instagram about the photo shoot.

“He looks like Thanos now,” a second person added, referring to the villain of Marvel’s “Avengers: Infinity War.”

“[He] looks like Lord Farquaad in Shrek,” a third troll posted.

Some came to his defense too. In 2022, Efron told People that an accident in 2013 left his jaw shattered causing the muscles in his face and jaw to enlarge.

“They just got really, really big,” Efron said at the time.

“The Iron Claw” hits theaters Dec. 22.