Missouri Constitution of 1945 Art. III, § 32. Vetoed bills reconsidered, when

Every bill presented to the governor and returned with his objections shall stand as reconsidered in the house to which it is returned. If the governor returns any bill with his objections on or after the fifth day before the last day upon which a session of the general assembly may consider bills, the general assembly shall automatically reconvene on the first Wednesday following the second Monday in September for a period not to exceed ten calendar days for the sole purpose of considering bills returned by the governor. The objections of the governor shall be entered upon the journal and the house shall proceed to consider the question pending, which shall be in this form: “Shall the bill pass, the objections of the governor thereto notwithstanding?” The vote upon this question shall be taken by yeas and nays and if two-thirds of the elected members of the house vote in the affirmative the presiding officer of that house shall certify that fact on the roll, attesting the same by his signature, and send the bill with the objections of the governor to the other house, in which like proceedings shall be had in relation thereto. The bill thus certified shall be deposited in the office of the secretary of state as an authentic act and shall become a law.