Although he has a criminal record, Matthew has been a good employee for his 4 months of employment. The plant manager understands that it is necessary to terminate Matthew's employment, but he would like to do so without notice for just cause and he would like to rely on the termination provision in the employment letter, which Matthew agreed to, and pay him 72 hours' pay in lieu of notice. The plant manager asks Donna for advice. What should Donna advise about the enforceability of the termination without just cause portion of contract?