The invention relates to a heat exchanger housing (1) for at least one heat exchanger for exchanging heat between a first fluid, in particular an exhaust gas or charge air, and a second fluid, in particular a coolant (6). According to the concept of the invention, a bypass duct (40) is integrated in the heat exchanger housing (1), with the housing having a housing body (10) with a chamber which is designed to be traversed by the second fluid and to hold a number of flow ducts which can be traversed by the first fluid; a bypass duct (40) which is designed to be traversed by the first fluid; with the chamber and the bypass duct (40) being formed in one piece with the housing body (10).