PARIS, France (AFP) — Chess No. 1 Magnus Carlsen has quit a world championship event in New York after being fined and threatened with exclusion for breaching the dress code by wearing jeans.

Carlsen was asked to change his clothes Friday at the World Rapid and Blitz Chess Championships after falling foul of the governing body’s regulations.

The chess federation (FIDE) said Carlsen rejected the opportunity to switch out of his jeans, and he was issued a fine of $200.

In a statement, FIDE said its rules “are designed to ensure professionalism and fairness for all participants.”

It cited the case of another competitor who was fined for wearing sports shoes but allowed to continue after changing into appropriate footwear.

Carlsen, 34, is a five-time world chess champion. The Norwegian is also the reigning champion in both the rapid and blitz chess competitions.

“I put on a shirt, jacket and honestly like I didn’t even think about jeans, even changed my shoes,” Carlsen told the chess channel Take Take Take.

“First of all, I got a fine which is fine, and then I got a warning that I would not be paired if I didn’t go change my clothes. They said that I could do it after the third round today.”

“I said ‘I’ll change tomorrow if that’s okay, I didn’t even realize it today’, but they said, ‘Well you have to change now.’ At that point it became a bit of a matter of principle for me.”

Carlsen said he would not appeal the decision.

“Honestly, I am too old at this point to care too much,” he said.

“Nobody wants to back down. I’ll probably head off to somewhere where the weather is a bit nicer than here.”