Proton‐defined stripe geometry GaAlAs laser diodes with multiple quantum well active layers grown by organometallic vapor phase epitaxy have been operated continuously at 5 mW/facet for over 1800 h at 70 °C and over 1100 h at 100 °C. With a 0.7‐eV activation energy, these times extrapolate respectively to 11.7 and 47.9 years of continuous operation at 20 °C. In the present mode of degradation, we estimate that the mean time to double the initial operating current is greater than 138 years at 20 °C.