PARIS (AP) — France is tightening its vaccination rules in a way that could put Novak Djokovic at risk of missing the French Open.

Starting Feb. 15, anyone who is not vaccinated against the coronavirus will need to show proof they tested positive for COVID-19 within the previous four months — down from the current six-month window — in order to enter sports venues in France.

The French law is central to the government’s plan for tackling the virus and aims to bar unvaccinated individuals from stadiums, restaurants, bars and other public places.

Djokovic, who is not vaccinated, said he tested positive in mid-December. Under the current rules with a six-month window, he could play in the French Open, which starts May 22. But if the new requirements stay in force until then, they are likely to rule him out unless he gets vaccinated or tests positive again at the right time.