When farmers use antifungal pesticides called triazoles to protect crops, the fungi can develop resistance to these chemicals. This study found that when the fungus Aspergillus fumigatus is exposed to the agricultural triazole tebuconazole, it can become resistant not only to that pesticide but also to clinical triazole drugs used to treat human fungal infections. The resistant fungi maintain this resistance even when the pesticide is removed, suggesting that environmental pesticide use may threaten the effectiveness of medical antifungal treatments.