Wis. Stat. § 767.375: Effect on transfers at death.

(1) Revocation of death provisions in marital property agreement. Unless the judgment provides otherwise, a judgment of annulment, divorce or legal separation revokes a provision in a marital property agreement under s. 766.58 that provides for any of the following:

(a) That, upon the death of either spouse, any of either or both spouses’ property, including after-acquired property, passes without probate to a designated person, trust or other entity by nontestamentary disposition.

(b) That one or both spouses will make a particular disposition in a will or other governing instrument, as defined in s. 854.01 (2).

(2) Revocation of revocable transfers at death. Unless sub. (1) applies, revocation of revocable transfers at death by a former spouse to the other former spouse, or to relatives of the other former spouse, under an instrument executed before the judgment of annulment, divorce or legal separation is governed by s. 854.15.