Small cell-derived, membrane-bound extracellular vesicles (exosomes) can be used therapeutically to deliver drugs or modify gene expression, but when given systemically it is difficult to target their distribution. Gao et al. developed a peptide, CP05, that binds to CD63, a protein expressed on exosomes. Painting exosomes with CP05 conjugated to a muscle-targeting peptide increased delivery of a splice-correcting oligomer to muscle, which increased dystrophin expression and muscle function in a mouse model of muscular dystrophy. CP05 could also isolate exosomes from human serum. This study demonstrates that CP05 can be used to capture and modify exosomes and their cargo for targeted delivery.