The invention relates to known housing seals of two housing parts lying against each other, a first housing part (1) having a first sealing surface (6) and a second housing part (2) having a second sealing surface (7), which housing seals are equipped with a seal (15), which is inserted into a groove (10) in the first sealing surface (6) of the first housing part (1), wherein the groove (10) is covered by the second sealing surface (7) of the second housing part (2). According to the invention, in order to prevent crevice corrosion, the groove (10) has an opening (11) between the sealing surfaces (6, 7), which is used to ventilate the groove (10) having the inserted seal. The invention is intended for water pumps, in particular for auxiliary water pumps of motor vehicles.