Ozzy Osbourne explained his doubts over the possibility of making an album with former Black Sabbath bandmate Tony Iommi.

The pair reunited to perform at the U.K.’s Commonwealth Games last month after Iommi recorded guitar parts for two tracks on Osbourne’s upcoming album Patient Number 9. In a recent interview, the singer hinted that a collaborative album might follow, and in a new interview with Kerrang! he elaborated on the idea.

“If Ozzy Osbourne and Tony Iommi do an album together, it’s going to sound like a Sabbath album,” he said. “Tony was the sound of Sabbath. There’s no getting away from the fact that, when he plays with me, it’ll be some kind of a reflection of that. Maybe the tracks he did on my album was like what Sabbath should have been had we stayed together.”

But, he stated, “I want to take it away from Sabbath. We put that band to bed. And if he wants to [turn it into another] Sabbath album, I’m not doing it.”

He also revealed why Iommi never previously guested on one of his records. “It was just that I never asked him,” he said. “I sang on one of his albums [in 2002], but I’d never given it a thought [that he could] play on one of mine, to be honest.”

Producer Andrew Watt made the change, Osbourne explained. “It was actually Andrew who said, ‘Why don’t you ask Tony Iommi if he wants to do something?’” he recalled. “I was like, ‘I know he’s going to tell me to go fuck myself.’ But you don’t know until you ask. When he sent [his tracks] over, I heard them and was just like, ‘Fuck me!’”

Osbourne will make his U.S. stage return Thursday when he plays the NFL season-opening ceremony. Patient Number 9 comes out Friday.