Low-temperature photoluminescence (PL) was used to investigate the optical properties of In0.10Ga0.90As/GaAs quantum wells grown on GaAs(001) substrates with a miscut angle of 0 degrees (nominal), 2 degrees, 4 degrees and 6 degrees towards [110]. The luminescence from the quantum wells grown on a vicinal surface exhibited a blueshift compared to the nominal case. An extra emission at low energy was only observed for the nominal sample and was related to In segregation. Its absence from the PL spectrum of quantum wells grown on vicinal surfaces is a strong indication that In segregation is modified on this type of surface. Theoretical calculations confirmed our experimental data.