Mich. Comp. Laws § 128.85

Sec. 5. A bond covering a county treasurer as required by sections 35 and 36 of 1846 RS 14, MCL 48.35 and 48.36, must be for the faithful and proper discharge of duties under this act, including the holding of money deposited under this act. The bond must be increased or decreased to reflect the amount of money held by the county treasurer under this act, as determined by the county board of commissioners.