The International Olympic Committee on Sunday adopted a new set of guidelines that will allow transgender athletes to compete in tournaments without having to undergo sex re-assignment surgery. While athletes transitioning to male can participate without restrictions, those transitioning to female will need to show that their testosterone levels have been below a particular cut-off point for a year before their event. According to the last set of guidelines announced in 2003, a transgender athlete had to have a reassignment surgery in addition to two years of hormone therapy before they were allowed to participate.

The new guidelines have been developed in keeping with current scientific, social and legal discourse on gender issues, officials said. While they are still recommendations, and not binding rules, all international sporting bodies can follow them and they also apply to the Rio Olympics later this year. “It is necessary to ensure insofar as possible that trans athletes are not excluded from the opportunity to participate in sporting competition,” the IOC said in a statement posted on its website.

The guidelines were approved after a meeting with Olympic officials and medical experts in Switzerland last year. Former IOC medical commission chairman Arne Ljungqvist told The Guardian that the new guidelines were developed because of growing social consensus and an eye on human rights issues.

The indecision and controversy surrounding transgender athletes in major sporting events is not new. In 2008, South African runner Caster Semenya was forced to undergo a “gender test” following her victory at the world championships. Last year, Olympic decathlon champion Caitlyn Jenner announced that she had transitioned into a woman. Over the decades, there has been no consensus on the exact scientific boundaries within which the two supposed sexes fall, leaving Olympics officials to repeatedly change their guidelines for athletes who cannot be conventionally classified.