Plant leaves are usually smooth and flat structures, optimised for photosynthesis. Recently, we identified two closely related genes in Arabidopsis thaliana that are differentially regulated by two master-regulators of leaf development called REVOLUTA (REV) and KANADI1. These newly discovered genes encode transcription factors (TFs) containing MYB DNA binding domains closely related to those of the KANADI gene family and are named KANLIKE1 (KANL1) and KANLIKE2 (KANL2). Using ChIP PCR, we found evidence that KANL1 and KANL2 are direct targets of REV and by creating CRISPR knockouts, we also discovered that kanl1kanl2 mutant leaves are curved rather than flat. This defect correlates with the ectopic expression of WOX1, which is a gene that promotes leaf expansion. By creating novel mutant combinations, we also found that KANL1 and KANL2 work redundantly with another well-known gene called AS2, to repress the formation of ectopic outgrowths from the adaxial leaf surface. These results reveal two new important players within the transcriptional network downstream of REV and KAN that ensures leaves develop a flat shape.