There is provided an elongate aerosol-generating device (100) having a polygonal transverse cross-section. The polygon comprises at least 6sides. The elongate aerosol-generating device may comprise a substrate receiving cavity (302) adapted to receive an aerosol-forming substrate, a heating element (406) adapted to heat an aerosol-forming substrate to generate an aerosol, and a power supply (506) adapted to provide power to the heating element. In addition, there is provided an aerosol-generating system, comprising an elongate aerosol-generating device according to any of the preceding claims, and a charging device (600) comprising a cavity (602) having a polygonal transverse cross-section corresponding to the polygonal transverse cross-section of said aerosol-generating device, the cavity being adapted to receive the elongate aerosol-generating device.
