An agreement to indemnify a person against an act thereafter to be done is void if the act be known by such person, at the time of doing it, to be unlawful.
Mont. Code Ann. § 28-11-302
Indemnity for future unlawful act void
En
Official source: Montana Code Annotated (Montana Legislature). Reproduced from public-domain Montana statutes; confirm against the official source for the current text. Not legal advice.