An aerosol-generating device for generating an aerosol by inductive heating of an aerosol-forming substrate is provided, the device including a device housing including a cavity configured to receive the aerosol-forming substrate; an induction source including an induction coil configured to generate an alternating magnetic field within the cavity, the induction coil being arranged around at least a portion of the cavity; a flux concentrator arranged around the induction coil and configured to distort the alternating magnetic field of the induction source towards the cavity; and a bond layer firmly coupled to a least a portion of the flux concentrator, the bond layer including or consisting of a poly(p-xylylene) polymer. There is also provided an aerosol-generating system including an aerosol-generating device including and an aerosol-generating article for the device, the article including an aerosol-forming substrate to be heated.