Face recognition declines with age, potentially due to impairments in integrating new information into existing memory representations. Face-adaptation studies provide a powerful approach to examine this process, as they assess how prior visual experience influences subsequent perception and memory of faces. Previous studies from our lab demonstrated comparable face adaptation effects for younger adults (YAs) and older adults (OAs) when adaptation and test phases in face-adaptation experiments were separated by short intervals (300 ms) and induced for non-configural facial attributes such as facial brightness and contrast, suggesting that adaptation is preserved across age. However, such short intervals could primarily represent low-level perceptual mechanisms. It therefore remains unclear whether the temporal robustness of face adaptation and thus adaptation on a more long-term memory level differs with age. In two online experiments, we examined adaptation for brightness (Experiment 1) and contrast (Experiment 2), increasing the interval between adaptation and test phases to five minutes—an interval that should involve long-term memory mechanisms. Both experiments revealed robust adaptation effects for YAs and OAs, with comparable effect magnitudes across groups. These findings show that face adaptation for brightness and contrast remains temporally robust in both younger and older adults. The adaptive updating of face representations with respect to these attributes appears stable across the adult lifespan, challenging the assumption of impairments in integrating new information into existing face memory representations in older adulthood.