Recently, the presence of basal-prismatic interfaces in hexagonal close packed metals became subject of intensive investigation. We model the {101¯2} twin in magnesium bounded by two types of boundaries, i.e. {101¯2} interface and basal-prismatic facets. The migration of all boundary types is mediated by the motion of interfacial disconnections. It was shown that basal-prismatic interfaces play an important role in twin growth. The lengths of basal-prismatic facets remain constant during migration independently of the applied strain. In contrast, the {101¯2} interfaces increase their lengths during growth.