PORTLAND, Maine (AP) — The state’s highest court says the Public Utilities Commission does not have authority over the phone system run by Maine’s corrections system.

In its unanimous decision, the Maine Supreme Judicial Court on Tuesday settled the issue of whether the Department of Corrections or the Public Utilities Commission has jurisdiction over the phone rates that apply to prison inmates.

The case began as a complaint by inmates over fees imposed on them. They appealed to the Public Utilities Commission, which ruled that it has jurisdiction.

In vacating the commission’s ruling, the supreme court ruled that one state agency doesn’t have the right to regulate another state agency.