A new Illinois law is meant to encourage people to seek help if they or friends suffer a drug overdose.

The law says people who seek medical treatment for an overdose are immune from prosecution on minor drug charges. That way, they can call for an ambulance or go to an emergency room without worrying that they'll end up in jail.

Gov. Pat Quinn signed the measure into law Monday. It takes effect June 1.

Someone who is found with large amounts of drugs after reporting an overdose could still be charged. With heroin, for instance, immunity would not apply to someone carrying more than three grams.