Although low concentrations of salt in food are appetitive, salt becomes aversive with increasing concentration, thus helping to avoid excessive consumption that would disrupt electrolyte homeostasis. The mechanism underlying this aversive response is unknown, but Oka et al. show that a high concentration of salt recruits bitter- and sour-sensing aversive pathways. Inhibition of activity in these pathways by gene silencing had no effect on the appetitive effect of salt; indeed, salt remained appetitive even at very high concentrations. The co-opting of aversive pathways could protect against harmful ingestion of large amounts of salt.