When young children interpret novel nouns, they tend to be very much affected by the perceptual features of the referent objects, especially shape. This article investigates whether children might inhibit a prepotent tendency to base novel nouns on the shape of referent objects in order to base them on conceptual features (i.e. taxonomic object categories). The study tested 3- to 5-year old children on a noun extension task, alongside a test of their inhibition and more general executive control ability. Noun extensions were related to inhibition ability, independent of age. Noun extensions were not related to individual differences in the general executive control task. This suggests a potential role for inhibition in extension which is independent of other aspects of cognitive development.