An oil sump 1 of an internal combustion engine has a recess 3, into which dips a suction funel 5 of an oil pump. The funnel is spaced slightly from the oil sump floor 7. A honeycomb-shaped insert 8 is positioned in the recess 3 at a slight spacing from the oil sump floor 7. The height b of the insert 8 amounts to a multiple of the spacing a from the oil sump floor and also a multiple of the side length c of the substantially square cross-section of the chambers 11 of the insert 8. As a result, the oil flowing back from the engine, which is strongly foamed with air because of the rotating motion of the crankshaft drive, can become de-foamed in the relatively high chambers 11, whereby the oil foam in the chambers 11 rises and air-free oil in the chambers drops down to the oil sump floor 7. This ensures that the oil pump, which is pumping out from the oil sump floor 7, essentially draws in air-free oil.