An aerosol-generating article (10) comprises an aerosol-generating substrate (12) and a mouthpiece (14) secured to a downstream end of the aerosol-generating substrate (12), the mouthpiece (14) comprising at least one segment of filter material (18, 20) and a liquid delivery element (22). The liquid delivery element (22) comprises: an upstream end and a downstream end; a deformable outer container (28) having at least one flexible wall (32) defining a cavity (40), the cavity (40) containing a liquid (42); and a frangible tubular element (30) mounted within the cavity (40) of the deformable outer container (28) and defining a longitudinal channel (46) extending through the deformable outer container (28) between the upstream end and the downstream end of the liquid delivery element (22).