Many job stress models emphasize the importance of job control as a resource that promotes well-being and performance. However, research has started to acknowledge that job control can sometimes also have negative effects. Our study adopts a self-control perspective to investigate these possible downsides. We hypothesized that job control should have negative effects on well-being and performance by enhancing self-control demands. However, we expected that only employees with low levels of trait self-control should experience negative effects of high job control due to increased self-control demands. We conducted a workplace simulation with an experimental manipulation of job control (high vs. low). We asked participants to complete an inbox task with work-related email inquiries and measured subjective well-being, as well as heart rate variability (HRV). Furthermore, we analyzed objective task performance. The findings revealed that, for individuals with low levels of trait self-control, job control negatively affected subjective well-being (i.e., anxiety and fatigue), but not HRV, through enhanced self-control demands. Although there was no evidence for mediating effects of self-control demands regarding performance, we found a (direct) moderation of trait self-control and job control in the form of lower performance of individuals with low trait self-control under high job control conditions. (PsycInfo Database Record (c) 2025 APA, all rights reserved).