The 'Jackass' boys are back together once again for the upcoming 'Jackass Forever'. But it hasn't always been a rosy reunion.

As well as issues surrounding former star Bam Margera not returning, it was also revealed that Steve-O and Johnny Knoxville had a falling out while negotiating pay for the film.

Steve-O spoke to Variety to clear up what happened.

"I was in shock. I was in disbelief when I learned that Knoxville was trying to make a fourth 'Jackass' movie after an entire decade of inactivity with the 'Jackass' brand", said the 47 year-old. "The contracts have never been fun but this time around, it was even less fun."

In the run up to the film, Steve-O went public about digging his heels in on contract negotiations which raised tensions with his co-star. He claimed he'd never pushed back on contracts for the previous films but had being building up his own brand over the decade since the previous film.

"I built myself up. I deserved more now because I worked for more. When my entertainment attorney says 'OK, go for it,' then I’m going to go for it."

However, Steve-O admits he could have gone about negotiations "a lot more smoothly".

"I blurted shit out during interviews that was counterproductive, so that’s what really pissed off Knoxville. We had a little rift, you know? My lawyer finally called me up and said, 'Hey, take it, dude. This is going to get ugly.' It might have gone up the smallest fraction of a number. But it did not go up in any sense for me to call it a win"

The two have patched everything up since and Steve-O was fully onboard for the fourth entry in the 'Jackass' franchise. A call between the stars was key to clearing the air.

"I said, 'Hey, I want to acknowledge the way I handled the whole contract situation — it was fucking bullshit, man.' I called to acknowledge it, and just put it out there that I was wrong and wanted to make it right. It was the most healing conversation that he and I had ever had. I felt emotional about it."

'Jackass Forever' releases in cinemas February 4.