Mich. Comp. Laws § 38.2743

Sec. 13. The trusts created by this act shall not be deemed to be invalid by reason of any indefiniteness or uncertainty of the persons designated as beneficiaries in this act and agreements creating the trusts, nor shall the trusts be deemed to be invalid as violating any existing law against perpetuities or against suspension of the power of alienation of title to property or against trusts for the purpose of the accumulation of income, but each trust may continue for the amount of time that may be necessary to accomplish the purpose for which it was created.