Mo. Rev. Stat. § 491.040: Sections 491.010 and 491.030 construed.

Nothing in sections 491.010 and 491.030 shall in any manner affect the law relating to the attestation of the execution of last wills and testaments, or of any other instrument required by law to be attested, nor shall they be so construed as to compel any person to subject himself, by his testimony, to any prosecution for a criminal offense.