An electrically heated aerosol-generating device includes a main housing having a cavity, a closure body engageable with the main housing to enclose a cartridge in the cavity, and a heater assembly. The heater assembly includes an elongate piercing assembly configured to extend into the open-ended passage of the cartridge and one or more electric heaters. The piercing assembly has a first hollow shaft portion connected to the main housing and a second hollow shaft portion connected to the closure body. The first and second hollow shaft portions have first and second piercing surfaces configured to breakthrough first and second frangible seals when the cartridge is enclosed in the cavity.