It is time for professional tennis to put an end to illegal coaching from the stands. For years they have ignored the problem, but penalties must now be imposed upon those who disregard the rules.

Players talking to their coaches during matches has become all too common in professional tennis. Coaches communicating with their players when it is prohibited is not a new issue but is an issue that has been ignored for too long. During Justine Henin’s comeback in 2010, her coach was caught signalling and communicating with her. At the 2006 U.S. Open, Maria Sharapova’s hitting partner was caught giving signals to Sharapova. In both cases, the chair umpire did nothing.

In 2013, Toni Nadal, Rafael Nadal’s coach, admitted that he coached Rafa from the stands. At the time, Toni told Tennis.com: “I talk to Rafa during matches. I know it’s not allowed, but I think that at my age I have nothing to hide.”

These are just a few of the innumerable cases in the past few years.

Coaches are allowed to cheer for their players but cannot exchange words or give any type of gestures or signals. The WTA allows coaching once per set during changeovers, with the exception of Grand Slams, while the ATP does not allow coaching during a match. Furthermore, when deciding on whether to challenge a call, players look to their boxes for advice. But that’s not allowed. Chair umpires are not supposed to allow a challenge if a player is caught looking to his or her box, though they often still allow them.

Both men and women players are allowed to receive coaching if there is an instance where players have to leave the court, like if there was a rain delay. Coaching on court is also acceptable in team tennis settings where there is a captain on court, such as Mylan World Team Tennis, Fed Cup and Davis Cup.

The rules are sometimes enforced, but not nearly enough.

This past weekend during the finals of Indian Wells, Jelena Jankovic, who is known for spirited conversations with herself and her box, was given a warning for a coaching violation. It was one of the few warnings that have been given this year.

So what’s so bad about getting coaching advice during a match? If one player receives extra coaching, it could give him or her an advantage over the opponent. It is fine if players direct a fist pump or a “c’mon!” at their box. Nevertheless, chair umpires and tournament directors need to be more aware of the amount of coaching that is happening from the stands and eject coaches that break the rules.

In fact, it would be smart for tournaments to plant officials in the stands to watch coaches to make sure that they aren’t trying to pass along advice to their players. Coaches who are found to break these rules should be fined and suspended from tournaments with escalating penalties for repeat offenders.

Tennis’ governing bodies need to come together and decide what to do because this form of cheating needs to stop. This blatant disregard for the integrity of the game is hurting everyone involved in the sport. Eventually there will be a big controversy if this is not addressed and tennis could end up losing