All plant leaves originate from an undifferentiated cell cluster, the shoot apical meristem (SAM), and undergo common developmental stages. Subtle differences in these stages generate numerous leaf shapes, from simple leaves with undivided blades (e.g. Arabidopsis) to compound leaves, which consist of several subunits called leaflets (e.g. tomato). Now, Naomi Ori and co-workers report that the transcription factor GOBLET, a homologue of the Arabidopsis NAM/CUC boundary genes, functions in tomato compound leaf development (p. 823). The authors show that GOBLET mRNA localises to the tissue boundaries between the SAM and leaf primordia, and also to the flanks of newly forming leaflets. This localisation is disrupted in loss- and gain-of-function goblet mutants, which both give rise to simpler leaf shapes. Leaf-specific expression of the microRNA miR164, a negative regulator of GOBLET, also results in simpler leaves, an effect conserved in another compound-leaved plant, Cardamine hirsuta. From their findings, the authors propose that the precise and context-dependent regulation of GOBLET is used to flexibly pattern leaf shapes.