US Open organisers have expressed regret at the warning given to Alize Cornet for changing her top on court at Flushing Meadows.
The Frenchwoman returned from the 10-minute heat break between the second and third sets during her first-round clash with Johanna Larsson of Sweden on Tuesday and realised she had her top on back to front.
Cornet quickly switched the top around standing behind the baseline and was astonished to be given a code violation by the umpire.
The decision caused a stir on social media and tournament organisers have now said Cornet should not have received a warning and will not face a fine.
"All players can change their shirts when sitting in the player chair. This is not considered a code violation," tournament organisers said in a statement.
"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.
"Female players, if they choose, may also change their shirts in a more private location close to the court, when available. They will not be assessed a bathroom break in this circumstance."
The WTA welcomed the US Open's response, saying in a statement "the code violation that USTA (United States Tennis Association) handed to Alize Cornet during her first round match at the US Open was unfair and it was not based on a WTA rule, as the WTA has no rule against a change of attire on court.
"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."