When children experience habitual peer difficulties, adults often remind them that many people care about them. How do such reminders of support impact children's emotional responses to acute experiences of peer disapproval? Intuitively, support reminders would exert compensatory effects attenuating the emotional impact of acute disapproval. Theory suggests, however, that support reminders might also lead to contrast effects magnifying the emotional impact of acute disapproval, especially among socially vulnerable children. These opposing perspectives were pitted against each other. In 2 experiments, children (aged 9-13, M[subscript age] = 11.5) were randomly assigned to reflect on their relationships with either supportive others (support condition) or mere acquaintances (control condition). Children experienced acute peer disapproval immediately after (Experiment 1) or before (Experiment 2) the manipulated support reminder. Among children who experienced higher levels of peer difficulties in their daily life, the support reminder increased externalized emotional reactivity and decreased internalized emotional recovery following disapproval. Thus, consistent with emotional contrast theory, support reminders magnified the disapproval-based emotional responses of socially vulnerable children.