An exhaust gas heat exchanger that includes a stack at least partially surrounded by a housing. The stack includes a first tube, a second tube, and a coolant duct between the first tube and the second tube. A fin is located within the coolant duct. The fin includes a first portion and a second portion and the first tube includes a first portion and a second portion. The first portion of the fin is fixed to the first portion of the first tube such that the first portion of the fin is coupled to the first portion of the first tube for movement with respect to the housing, and the second portion of the fin is supported in the housing for movement relative to the second portion of the first tube to permit movement of the second portion of the first tube with respect to the second portion of the fin.