CHICAGO (AP) — The Illinois State Board of Education voted unanimously to adopt the state’s most restrictive permanent rules that ban the use of locked seclusion rooms and prohibit schools from using prone restraint.

The new rules approved on Tuesday specify that seclusion may not be used “as discipline or punishment, convenience for staff, retaliation, a substitute for appropriate educational or behavioral support, a routine safety matter, or to prevent property damage.”

The vote comes after a Chicago Tribune and ProPublica Illinois investigation in November revealed extensive misuse of isolated timeout and restraint in Illinois schools.

The new rules ban locks on rooms and employees from holding the doors shut.