How do young children decide to trust testimony that contradicts their initial beliefs? The current study examined whether children rely on cues to informant credibility (i.e., history of accuracy) to determine if they would endorse an unexpected label from an informant. Three- and 4-year-olds (N = 60) saw a picture of a hybrid artifact that consisted of features of two typical familiar artifacts. Children made initial judgments about the name of the hybrid object and subsequently received a different name offered by an informant who had earlier either accurately or inaccurately named familiar objects. Children were more willing to revise their own judgment and accept the unexpected label if it was from a previously accurate informant than if it was from someone who had made obvious naming errors. This suggests that preschool-aged children selectively revise their own knowledge; they are more trusting toward sources proven accurate than inaccurate.