A valve comprises a valve body delimiting a passage for exhaust gases, a flap arranged in the valve body, and a drive shaft configured to drive the flap, and which is integrally secured to the flap. At least one guide bearing is configured to guide the drive shaft of the flap in rotation in relation to the valve body, and is connected to the valve body. The valve also includes an actuator and a transmission comprising an adapter rigidly attached directly to the drive shaft of the flap. The transmission is arranged in order to transmit a motor torque between the actuator and the adapter. The adapter has a contact surface that is in sealed contact with a complementary surface provided on the guide bearing.