Chief Keef is headed back to jail … and proudly blasted the news out to the world after a judge slapped him with a 90 day sentence.
Keef, aka Keith Cozart, tweeted … “Judge Putting me Back in jail See y”all later.”
A Chicago judge sent Keef to a jail rehab facility because he reportedly failed a random drug test.
As we previously reported … the 18-year-old rapper gets tested as part of his probation for a speeding ticket — cops clocked him doing 110 mph in a 55, back in May.
This is Chief”s second F on a drug test — just last month he got 20 days in jail, but was released shortly after due to jail overcrowding.