An aerosol-generating system is provided, including an aerosol-generating device in cooperation with an aerosol-generating article. The article includes a first sealed compartment having a tubular porous element and a delivery enhancing compound sorbed thereon; and a second compartment having a volatile liquid. The device includes an outer housing adapted to receive the article; an elongate piercing member for piercing the first and second compartments. The elongate piercing member includes a piercing portion adjacent a distal end of the elongate piercing member; a shaft portion; and an obstructing portion adjacent a proximal end of the elongate piercing member. The piercing portion has a maximum diameter greater than the diameter of the shaft portion, and the obstructing portion has an outer diameter such that it fits within the tubular porous element of the article when the article is received in the device. A corresponding aerosol-generating device and aerosol-generating article are also provided.