Indian Wells - Serena Williams on Thursday defended her use of a TUE (therapeutic use exemption) at the 2015 French Open, saying she uses them regularly and has never tested positive for illegal substances. 

Williams was asked about her use of TUE's following her first round victory over Zarina Diyas of Kazakhstan 7-5, 6-3 at the WTA Indian Wells tournament. 

"I have never tested positive. I have always done the TUE so you should fact check that," Williams said. 

"I wasn't going to play (the French Open) unless I had a TUE because if you remember that year I was incredibly sick." 

Williams insisted she did nothing wrong and that she requested the TUE in 2015 to fight the illness. She skipped practice sessions and needed five three-set wins before eventually claiming the title over Lucie Safarova. 

"I am never, ever going to take an advantage over someone else. That is not who I am." 

Reports show Williams was given approval for a TUE for the corticosteroid anti-inflammatory prednisone to help to alleviate the symptoms. 

"I don't know how I even won the [tournament], and I said I literally can't play the final," Williams said. 

"I have played over 20 years and I have always been extremely honest and that is one thing I take pride on especially having a daughter and having a kid. 

"I would never be able to look my kid in the eye and say 'Mom cheated' or Mom did something like that. 

"That is totally irresponsible and even before that I've always had that attitude."