New York - The US Open says it "regrets" Alize Cornet receiving a code violation for taking her shirt off and switching it around on court.
Cornet changed shirts off-court after the second set of her match against Johanna Larsson on Tuesday, but when she returned to the court, she realised she had put her shirt on back to front.
She then took it off and put it on the right way around, before receiving the code violation from the umpire.
The decision to penalise Cornet for her actions was roundly criticised on social media, with many accusing the tournament of sexism.
The reaction has prompted a response from the US Open, which said in a statement: "All players can change their shirt while sitting in the player chair. This is not considered a code violation. We regret that a code violation was assessed to Ms Cornet yesterday.
"We have clarified the policy to ensure this will not happen moving forward. Fortunately, she was only assessed a warning with no further penalty or fine."
The Women's Tennis Association also spoke out on the issue, making it clear that the violation was not based on any of their own rules.
"The code violation that USTA handed to Alize Cornet during here first-round match at the US Open was unfair and it was not based on a WTA rule, as WTA has no rule against a change of attire on court," the statement read.
"The WTA has always been and always will be a pioneer for women and women's sports. This code violation came under the Grand Slam rules and we are pleased to see the USTA has now changed this policy. Alize did nothing wrong."