Seven-time Tour de France winner Lance Armstrong announced on Twitter Monday that this year’s Tour with his RadioShack teammates will his final one.

“And yes, this will be (my) final Tour de France. It’s been a great ride. Looking forward to three great weeks,” the 38-year-old wrote.

Realizing his tweet included a mistake, Armstrong then tweeted, “Doh, sorry, meant “my” final Tour.”

On Saturday, Armstrong will lead team RadioShack to begin his bid for an eighth Tour de France title.

Monday’s announcement comes just one month after the Texan found himself embroiled in new doping allegations, dismissing accusations leveled by his former teammate Floyd Landis.

Landis, who was stripped of his 2006 Tour de France title after a positive drug test, pointed the finger at numerous cyclists, including Armstrong. Armstrong was quick to attack Landis’ credibility.

Armstrong beat cancer in 1998, then went on to win seven consecutive yellow jerseys from 1999-2005. He then retired, but then returned to the sport last year.

Armstrong placed third at the 2009 Tour. This year he finished second in the Tour of Switzerland and third in the Tour of Luxembourg. He crashed out of the Tour of California on home soil in May.

Armstrong will line up at this year’s Tour with a team that includes former Tour runner-up Andreas Klöden of Germany, Americans Levi Leipheimer and Chris Horner, plus several other experienced stage race campaigners.