Players at Euro 2016 could be tested for drugs in the middle of the night after France decided to pass a section of the World-Anti Doping Agency (WADA) code into law.
Previously athletes could not be tested between 11 p.m. and 6 a.m. but it will soon be possible for drug testers in France to call on them in the early hours.
"These nocturnal inspections are allowed under strictly supervised conditions from 11 p.m. to 6 a.m. in the morning," Thierry Braillard, the French Secretary of State for Sport, told media.
"They can only act with the consent of the athlete, who will be contacted quarterly to find out if he accepts them."
Overnight checks would be carried out when authorities had "serious suspicions" that an athlete might be doping.
If consent for testing is not granted, Braillard said a court order could be sought. French sports associations have six months to register the amendment in their rules and regulations.
The French Minister of Sport, Patrick Kanner, presented the change on Wednesday, the last day it was legally possible for its passage by cabinet.
Braillard told AFP its implementation had proved problematic due to constitutional constraints and because it is illegal for authorities in France to forcibly enter someone's home after 11 p.m. unless that person is under suspicion of being involved in terrorism or organised crime.
France was one of the last countries to submit anti-doping rules to WADA that were fully in line with the 2015 World Anti-Doping Code.
The issue was highlighted when cycling's independent testing body realised that they were not able to carry out night-time inspections during the Tour de France in July.
Cycling authorities had introduced the testing policy to crackdown on microdosing, which sees riders being administered with performance-enhancers like EPO overnight but which pass through the body by morning.
The French government was keen to make the change to help the country's chances of making a successful bid to host the 2024 Olympics.