Saul 'Canelo' Alvarez has signed up for year-round testing with the Voluntary Anti-Doping Association (VADA) after losing his WBC ranking.
The Mexican was handed a six-month suspension by the Nevada State Athletic Commission that runs until September after he tested positive for trace levels of the banned substance clenbuterol.
But Alvarez's camp maintained his innocence, blaming the finding on contaminated meat.
WBC president Mauricio Sulaiman this week said Alvarez was removed from their middleweight rankings after "he refused to sign up for the clean boxing programme as stated in the rules", but the 27-year-old has now agreed to regular testing.
"I want to let you know that I just signed the contract with @Vada_Testing for year-round testing," he posted on Twitter.
Alvarez will be looking to reschedule a fight with Gennady Golovkin on his return, having been forced to postpone their May 5 Las Vegas bout.
The first meeting between the pair ended in a controversial draw last September.