A rotary internal combustion engine having an insert opening defined in a hot area of one of the walls of the stator body and in communication with its internal cavity. A cooling jacket is received in and lines the insert opening. An insert is sealingly received in the cooling jacket and made of a material having a greater heat resistance than that of the wall. The cooling jacket extends between the insert and the wall along most of the length of the insert to prevent direct contact between the insert and the wall. A cooling gallery surrounds the cooling jacket and the insert, and is defined at least in part by the cooling jacket such that a coolant circulated therein contacts the cooling jacket. The cooling jacket is located between the cooling gallery and the insert.