A heat exchanger, e.g., an indirect charge air cooler for an internal combustion engine, is disclosed. The heat exchanger includes a plurality of tubes that provide a first channel system for a first fluid, and a second channel system for a second fluid disposed between the plurality of tubes that is fluidically separated from the first channel system. Two opposite side parts for fluidically bounding the second channel system are provided, between which the plurality of tubes are arranged. At least one frame part is soldered together with a respective outer edge of the two side parts. The outer edge of a side part includes a tab bent over S-shaped as edge reinforcement with a first tab section solder-plated on an outside and a second tab section solder-plated on an inside. The frame part has an S-shaped cross section with a first receptacle that receives the first tab section.