Mich. Comp. Laws § 554.33: Expectant estates; authorized method of defeasance, effect on original validity.

Sec. 33.

The last preceding section shall not be construed to prevent an expectant estate from being defeated in any manner, or by any act or means which the party creating such estate shall, in the creation thereof, have provided or authorized; nor shall an expectant estate thus liable to be defeated, be on that ground adjudged void in its creation.