Mich. Comp. Laws § 26.4

Sec. 4. Each bidder shall deposit with the state treasurer before making his proposal a certified check for the sum of 1,000 dollars which is to be forfeited to the state in case he shall fail to enter into a contract in accordance with this act if said board shall declare him to be the successful bidder, and he shall take a receipt from said treasurer and deposit it with his proposal.