For cases in which precise information is practically or actually unknowable, certainty and precision can indicate a lack of competence, while expressions of ignorance may indicate greater expertise. In two experiments, we investigated whether children and adults are able to use this “virtuous ignorance” as a cue to expertise. Experiment 1 found that adults and children older than 9 years selected confident informants for knowable information and ignorant informants for unknowable information. However, 5-7-year-olds overwhelmingly favored a confident informant, even when such precision was completely implausible. In Experiment 2, we demonstrated that 5-8-year-olds and adults are both able to distinguish between knowable and unknowable items when asked how difficult the information would be to acquire, but those same children still failed to reject the precise and confident informant for unknowable items. We suggest that children have difficulty integrating information about the knowability of particular facts into their evaluations of expertise.