A valve includes a valve body having an exhaust gas inlet and an exhaust gas outlet, the valve body defining an exhaust gas circulation passage between the exhaust gas inlet and the exhaust gas outlet. A flap is arranged in the valve body and a shaft drives the flap in rotation with respect to the valve body. At least one guide bearing guides the drive shaft of the flap for rotation relative to the valve body. The guide bearing is engaged through an orifice of the valve body, with an inner end of the guide bearing being located inside the valve body. A first tube is engaged in one of the exhaust gas inlet and exhaust gas outlet and abuts against the inner end of the guide bearing.