Double‐heterojunction Al0.3Ga0.7As/Al0.08Ga0.92As lasers (oxide‐striped and Al2O3facet coated) were subjected to step‐temperature aging from 60 to 100 °C. The change in threshold current and spontaneous output was monitored at 22 °C. The average time required for a 20% pulsed threshold current increases from about 500 h, when operating at 100 °C, to about 5000 h at 70 °C. At 22 °C, the extrapolated time is about 106h. The time needed for a 50% spontaneous emission reduction is of the same order of magnitude. The resulting ’’activation energies’’ are ∼0.95 eV for laser degradation and ∼1.1 eV for the spontaneous output decrease.