Actress Lindsay Lohan is expected to appear in court Friday after a judge revoked her probation earlier in the week.

Judge Elden Fox revoked Lohan's probation Monday and signed a bench warrant for her arrest, but the judge is holding it until a hearing at 8:30 a.m. Friday (11:30 a.m. ET), according to Los Angeles Superior Court spokesman Allan Parachini.

Lohan's supervised probation for a 2007 drunken driving conviction requires frequent drug tests. The judge warned her last month any failure could send her back to jail.

"Regrettably, I did in fact fail my most recent drug test and if I am asked, I am prepared to appear before judge Fox next week as a result," Lohan tweeted on September 17.