An exhaust gas recirculation cooler may include a housing and a first wall. The housing may include an exhaust gas region, a coolant region, an exhaust gas inlet, and an exhaust gas outlet. The first wall may be fixed within the housing and may separate the exhaust gas region from the coolant region. The first wall may include a first portion formed from a first material and facing the exhaust gas region and a second portion formed from a second material and facing the coolant region. One of the first and second materials may have a coefficient of thermal expansion that is greater than the other of the first and second materials. The first wall may be deflected toward one of the exhaust gas region and the coolant region during cooler operation based on a difference in the coefficient of thermal expansion of the first and second materials.