An exhaust mixer arrangement for a gas turbine engine comprises an exhaust cone, a lobed exhaust mixer surrounding at least a portion of the exhaust cone and a cover mounted to an outer surface of the exhaust cone. The cover and the outer surface of the exhaust cone define a dead-end cavity for receiving a stiffener ring. A plurality of circumferentially spaced-apart struts interconnect at least a number of lobes of the lobed exhaust mixer to the stiffener ring.