Mich. Comp. Laws § 87.39: Increase or diminishment of salary during term prohibited; exception; eligibility for office resigned or vacated.

Sec. 39.

The salary or rate of compensation for any officer elected by authority of this act shall not be increased or diminished during the term of office, except as provided in section 40; and no person who shall have resigned or vacated any elective office shall be eligible to the same office during the term for which he was elected or appointed when during the same time the salary or rate of compensation has been increased except in the event of an increase pursuant to section 40.