The mouthpiece for an aerosol-generating article comprises a housing with an inlet end, configured to allow an aerosol to flow into the mouthpiece, an outlet end, configured to allow the aerosol to flow out of the mouthpiece, and an aerosol flow path extending between the inlet and the outlet end. The mouthpiece is formed such that the flow direction of the aerosol is reversed at least once between the inlet and the outlet end. The invention also concerns an aerosol-generating system comprising an aerosol-generating device and the mouthpiece, as well as a method for assembling the mouthpiece.