Peroxisomes serve as organelles for cellular detoxification, targeting reactive oxygen species or providing sites for the breakdown of amino acids, lipids and nucleotides. How peroxisomes function during changing cellular and environmental conditions is not understood, in particular how the peroxisome matrix changes its protein content. In this issue, two research groups report the identification of a new peroxisomal import receptor, Pex9, which is induced when oleic acid is the sole carbon source in Saccharomyces cerevisiae. Ralf Erdmann and colleagues (p. 4057) identify Pex9 by phylogenetic analysis in which Pex9 shows high similarity to the conserved import receptor Pex5, which recognises peroxisomal proteins carrying a type 1 peroxisomal targeting signal (PTS1). The authors show that Pex9 is a cytosolic and membrane-bound peroxisome import receptor for the PTS1-containing malate synthases Mls1 and Mls2. Both of these peroxisome matrix proteins interact with Pex9, as well as the PTS1-receptor docking protein Pex14. Furthermore, they find that Pex9 is present in the cells in oleate-containing medium, but not when glucose or ethanol is the only carbon source. Einat Zalckvar, Maya Schuldiner and co-workers (p. 4067) performed a high-content microscopic screen to assess protein localisation changes during growth in oleate. Among other factors, the newly identified Pex9 localises to peroxisomes, and continues to do so in the absence of the Pex5 targeting receptor. Similar to the study by Erdmann and colleagues, the authors show that Pex9 affects the targeting of the PTS1-containing matrix proteins Mls1 and Mls2, and also the glutathione transferase Gto1. These two complementary studies reveal a complexity of the targeting pathways to peroxisomes and the capacity of the peroxisome to adapt to environmental changes such as the source of carbon.