Mich. Comp. Laws § 750.145g

Sec. 145g. If a person is convicted of a second or subsequent offense under section 145c, the sentence imposed for a second or subsequent offense is a mandatory minimum sentence of not less than 5 years. For the purposes of this section, an offense is considered a second or subsequent offense if, prior to conviction of the second or subsequent offense, the person has been convicted under section 145c or of another crime involving a sexual offense against a minor.