Nearly four years after Chicago decriminalized marijuana, its home state did the same. Illinois residents found in possession of 10 grams or less of pot will no longer face jail time for carrying the drug—just a fine of up to $200. It's the twenty-first state to enact a marijuana decriminalization policy.

The bill, passed Friday, goes into effect immediately and will also expunge offenders' records biannually to prevent them from permanently possessing a criminal record. 

"We applaud Gov. Rauner and the legislature for replacing Illinois’s needlessly draconian marijuana possession law with a much more sensible policy. This commonsense legislation will prevent countless citizens from having their lives turned upside down by a marijuana possession arrest," Chris Lindsey, senior legislative counsel for the Marijuana Policy Project, said in a statement released Friday.

The bill marks an effort by Republican Gov. Bruce Rauner and a largely Democratic legislature to reform the state's criminal justice system by combating the overwhelming number of arrests of small-scale drug offenders, which disproportionately affect the state's black population. (One Urban Institute report from 2013 showed that black Illinois residents were incarcerated at nine times the rate of white residents.)

Before the law, those found in possession of 2.5 grams of marijuana or less faced 30 days of jail time, while those in possession of 2.5-10 grams could spend up to six months in jail. Both misdemeanors also carried fines of up to $1,500. 

The fines associated with carrying 10 grams of marijuana apply only to residents who don't live in one of the 100 communities with existing decriminalization laws. Chicago residents, for example, could still face fines ranging from $250 to $500 for possessing up to 15 grams of marijuana.