UFC heavyweight champion Cain Velasquez is starting to speak his mind on the use of illegal drugs in MMA.

Velasquez, who will defend his title in May against Antonio Silva at UFC 160, recently told MMAFighting.com that he believes the sport needs to be as clean as possible.

“There’s rules out there. We all need to follow the same rules. Me, I’m a natural athlete. I think all my competitors should be the same. We should be all equal. Nobody should have an advantage like that on their side,” Velasquez said.

Recently, Lavar Johnson failed a drug test and was released by the UFC. Alistair Overeem tested for elevated levels of testosterone last year and was suspended, while countless other fighters have also failed to pass the test.

Velasquez, who trains with Daniel Cormier, said he would be a firm believer in tougher testing. And, knows that his and his teammate are two of the cleanest athletes in the sport “just by looking at us.”

“You can tell that we don’t do anything. Or if we do, it’s not very good stuff,” Velasquez joked. “Being natural, I think, is the best way to be even on the playing field.”

If the UFC is adamant on cracking down on illegal drugs being used, they will form a way to test fighters more often.