Chris Brown tested positive for marijuana use and will have a probation violation hearing on Novermber 1, a judge ordered Monday.
Brown is on five years probation for a 2009 assault on his then-girlfriend, singer Rihanna.
The positive test occurred in Virginia, Superior Court Judge Patricia Schnegg indicated during Monday's hearing.
She said Brown, 23, had told authorities that he ingested the marijuana in California, where he has a medical marijuana card.
Brown lived in his hometown of Richmond, Virginia, while performing his court-ordered community service.
On Monday morning Rihanna tweeted: "I'm praying for you and wishing u the best today!" Brown responded, "Thank u so much."