A DC motor is disclosed which includes a motor housing and at least one connection module adapted to be installed on the motor housing. The DC motor can be compact, flexibly adaptable to customer requirements and also easily installable in the case of a confined installation space. For this purpose, the motor housing can include a front-sided centering elevation or centering recess which cooperates with a centering recess or a centering elevation on the connection module. The connection module can be freely rotatable in a mounting state on the motor housing, and non-rotatably connected to the motor housing in the mounted state.