An oil pump housing of an internal combustion engine flanged to a crankshaft housing, which includes, but is not limited to an oil pump housing wall. The oil pump housing has an oil collecting tray in an upper region of the oil pump housing wall. An oil return channel is integrated in the oil pump housing. An oil return channel extends from an oil inlet opening in the oil collecting tray as far as an oil outlet opening in an area below an oil pan level.