The good corrosion resistance of the M5_Framatome cladding used in pressurised water reactors (PWR) may be due to the irradiation induced modifications of this alloy. Several ion irradiation tests were performed on the M5_Framatome alloy to reproduce the in-core metallurgical changes, followed by corrosion tests on the irradiated samples. Proton irradiation experiments at 350 °C produced long, nanometric niobium-rich precipitates. After irradiation, a significant decrease in the oxidation rate could be observed, highlighting the beneficial effect of irradiation on the corrosion behaviour. In addition, the amorphisation of Zr(Nb, Fe)₂ intermetallic precipitates did not change the oxidation rate of the M5_Framatome alloy.