The invention relates to an internal combustion engine (1), in particular in a motor vehicle, comprising at least one cylinder (3) that defines a combustion chamber (4) and in which a piston (5) can be adjusted with regard to stroke. Each cylinder (3) comprises at least one intake opening (6) for a fresh mixture. Each intake opening (6) is associated with an intake valve (7) that works together with an associated valve seat (8) in order to control the intake opening (6). At least one such intake opening (6) is provided with a guide mask (9) that laterally encloses the respective valve seat (8) on a side that is opposite the respective combustion chamber (4) along a delimited circumferential section. Each intake opening (6) is associated with an intake canal (10). In order to improve the operation of the internal combustion engine (1), at least one intake canal (10) leading to a masked intake opening (6) is associated with an additional valve (11) for controlling the intake canal (10).