Dwayne Johnson is revealing what’s behind his now-notorious beef with his Fast 8 co-star Vin Diesel .

In a new interview with Rolling Stone, Johnson looks back on his public feud with the action star and explains what caused them to butt heads on The Fate of the Furious set in 2016.

The first sign of trouble came back in August 2016 when Johnson posted a message on his Instagram venting his frustrations over filming. While he thanked his hard-working crew and female co-stars, Johnson slammed some his male co-stars writing, “Some conduct themselves as stand up men and true professionals, while others don’t. The ones that don’t are too chicken s–t to do anything about it anyway. Candy asses.”

It soon became clear to all that Diesel was the co-worker being criticized.

Almost two years later, Johnson is talking to Rolling Stone about how the actor’s relationship became so strained that they couldn’t film or be on set at the same time.

“That is correct,” confirms Johnson in the interview. “We were not in any scenes together.”

But what was it that caused all the on-set animosity?

Johnson now says that their trouble ultimately came down to a disagreement about professionalism.

“Vin and I had a few discussions, including an important face-to-face in my trailer,” he says in the interview. “And what I came to realize is that we have a fundamental difference in philosophies on how we approach movie-making and collaborating.”

Despite their rocky relationship, it appears those conversations helped Johnson to understand Diesel a bit more.

“It took me some time, but I’m grateful for that clarity. Whether we work together again or not,” he explains. “But I wish him all the best, and I harbor no ill will there, just because of the clarity we have.”

After reconsidering his choice of words, Johnson laughed and continues, “Actually, you can erase that last part about ‘no ill will.’ We’ll just keep it with the clarity.”

While a few years have passed since the infamous feud, Johnson is unsure of his future with the franchise.

When asked if he would return for the ninth Fast & Furious installment, he replied, “I’m not quite sure. Right now I’m concentrating on making the spin-off as good as it can be.”

The spin-off, Hobbs and Shaw, also co-stars Jason Statham and is due next year.

Johnson’s latest film, Rampage, slams into theaters Apr. 13.