Sunday wasn’t the first time we’ve seen Novak Djokovic express his frustration and anger on a tennis court.

He’s been known to smash his racket, and his actions on Sunday during a match at the 2020 U.S. Open — he hit a ball out of frustration that hit a line judge — lead to the No. 1 seed on the men’s side to default, which was completely justified given the rules in the ITF rulebook.

People on Twitter also unearthed video from a press conference in 2016, when Djokovic was asked about behavior like that, which included hitting a ball into the crowd at the ATP Finals in London and throwing his racket at the French Open that same year (the video of that incident is below).

“Does it concern you one day that will cost you dearly? If it hit someone …” a reporter asked, to which Djokovic scoffed.

“You guys are unbelievable,” he remarked at the time.

It did end up costing him, four years later.