An electrically heated aerosol-generating device and system are provided, the device including an outer housing having a cavity configured to receive an aerosol-generating substrate; an electrical heater including at least one heating element configured to heat the aerosol-generating substrate in the cavity to generate an aerosol; at least one air inlet, at least one air outlet; an airflow pathway extending from the at least one air inlet, through the cavity, to the at least one air outlet; means for determining the resistance-to-draw of the airflow pathway; and means for adjusting the resistance-to-draw of the airflow pathway in dependence on the determined resistance-to-draw. The system comprises an electrically heated aerosol-generating device and an aerosol-forming substrate comprising tobacco.