Ozzy Osbourne says he and his wife Sharon have expanded a suicide pact that she first revealed in a 2007 autobiography.

Initially, the two pledged to take one another to an Switzerland-based assisted dying organization called Dignitas if they developed Alzheimer's. Now, Osbourne -- who has had Sharon as a business manager for years, as well -- tells The Mirror that their pact also includes other catastophic conditions.

"If I can't live my life the way I'm living it now -- and I don't mean financially -- then that's it," Osbourne says. "If I can't get up and go to the bathroom myself and I've got tubes up my ass and an enema in my throat, then I've said to Sharon, 'Just turn the machine off.' If I had a stroke and was paralyzed, I don't want to be here."

Osbourne says he first began considering end-of-life measures after a quad-bike crash some 11 years ago. The Black Sabbath frontman's heart stopped twice as medical professionals worked to save him; they later informed Osbourne that he was very nearly paralyzed from the neck down in the mishap. "The quad-bike accident was quite a wake-up call and the doctor said I had been very, very lucky," Osbourne adds. “My ego had been running the show and for the first time I realised I wasn’t Superman."

The Osbournes just celebrated their 32nd anniversary on Friday (July 4), a moment that Ozzy shared during Black Sabbath's British Summer Time festival appearance in Hyde Park: "Do you know what day it is today?" he asked the crowd. "It's my f---ing wedding anniversary!"