The effectiveness of the potent antifungal drug fluconazole is being compromised by the rise of drug-resistant fungal pathogens. While inhibition of Hsp90 or calcineurin can reverse drug resistance in Candida, such inhibitors also impair the homologous human host protein and fungal-selective chemosensitizers remain rare. The MLPCN library was screened to identify compounds that selectively reverse fluconazole resistance in a Candida albicans clinical isolate, while having no antifungal activity when administered as a single agent. A piperazinyl quinoline was identified as a new small-molecule probe (ML189) satisfying these criteria.