Mo. Rev. Stat. § 41.390: Enlisted men — qualifications — term — oath — penalty for false statements.

1. The qualifications for enlistment and reenlistment in the organized militia shall be determined as set forth in section 41.050. The term of enlistment and form of oath shall at all times conform to the requirements of the laws of the United States and of this state and the regulations from time to time promulgated for the governing of the Armed Forces of the United States and of this state.

2. Every person who enlists or reenlists shall sign the enlistment papers and take the oath required by the laws and regulations of this state and the United States. Such oath may be administered by any commissioned officer or warrant officer of the organized militia of this state or of the Armed Forces of the United States. Any willful false statement so sworn to is perjury.