Wis. Stat. § 180.1803: Election.

A corporation organized under this chapter and having 50 or fewer shareholders at the time of election may become a statutory close corporation by amending its articles of incorporation to include the statement required under s. 180.1801. The amendment shall be approved by the holders of at least two-thirds of the votes of each class or series of shares of the corporation, voting as separate voting groups, whether or not otherwise entitled to vote on amendments. If the amendment is approved, a shareholder who did not vote in favor of the amendment is entitled to assert dissenters’ rights under ss. 180.1301 to 180.1331.