Serena Williams coach has called for on-court coaching to be permitted.

Patrick Mouratoglou admitted gesturing to Williams from the stands during her match with  Japanese Naomi Osaka — in contravention of U.S. open and other grand slam tournament rules — but the american was left infuriated at the umpire’s strict interpretation of the rule.

Williams said she had not seen Mouratoglou’s signal and that she had “never cheated in her life.

The incident and the ensuing row resulted in a game penalty and a $17, thousand dollars fine for Williams, and divided tennis by triggering a debate about sexism in the sport.

Coaching during matches is permitted in some women’s events, but grand slam tournaments are among those which do not allow it.

The U.S. open permitted players to talk to their coaches during qualifying and junior matches, but any move to allow it during main draw matches would need to be unilateral among the four slams.

The Frenchman said it was time coaching was both recognized and valued, because the fallout following last month’s U.S. open final made it look as though coaching was shameful.

Representatives of the four grand slam tournaments are expected to meet before the end of the year, at which point the future of mid-match coaching will be a topic of conversation.