Positive affect has been shown to promote task-switching performance in healthy young adults. Given the well-documented age-related decline in executive functioning, we asked whether induced positive affect also helps to improve task-switching performance in older adults. Sixty-eight younger and older adults performed a switching task before and after they had watched cartoon clips (positive affect group) or documentaries (neutral affect group). Positive affect was associated with reduced error rates across all trial types in both age groups. In older adults, the increase in accuracy came at the expense of slower response times for task-switch trials, resulting in greater switch costs. This pattern of findings is inconsistent with the popular notion that positive affect supports greater cognitive flexibility. Instead, positive affect may trigger adjustments in response control settings - such as a shift in the speed-accuracy trade-off toward more cautious responding - depending on the experienced level of task difficulty.