There is provided an aerosol generating system for heating a liquid aerosol-forming substrate. The system comprises: an aerosol-forming chamber (127)； and leakage prevention means (305,307) configured to prevent or reduce leakage of liquid aerosol condensate from the aerosol generating system. The leakage prevention means may comprise one or more of: at least one cavity in a wall of the aerosol-forming chamber, for collecting droplets of condensed liquid aerosol-forming substrate； at least one hooked member for collecting droplets of condensed liquid aerosol-forming substrate； an impactor for disrupting airflow in the aerosol-forming chamber so as to collect liquid droplets； and a closure member for substantially sealing the aerosol-forming chamber when the aerosol generating system is not in use.
