San Mateo County Superior Court Judge Mark Forcum Tuesday ordered the former disco star to complete seven months of drug treatment and abstain from drugs and alcohol, or face three years and eight months in prison, the San Francisco Chronicle reported Wednesday.
"He has a lot of potential in life which remains untapped, and it's not going to be realized unless he conquers his addiction," Forcum said. "He seems sincere to me about wanting to do that."
Willis, 55, pleaded no contest under a plea agreement reached in July that combined three cases against him.
Prosecutor Elaine Tipton said Willis -- who racked up eight prior convictions during 18 years -- should look upon the court's leniency as "one last chance."
Willis has said he planned to write a book and tour next year, the newspaper said.