Background: People with depression maintain negative expectations despite disconfirming positive experiences by reappraising or discarding novel positive information, referred to as “cognitive immunisation”. A second body of literature suggests that negative mood can negatively affect information processing. Bridging these two lines of research, the present study examined the interplay of cognitive immunisation and negative mood in the context of expectation update.Methods: In a student sample (N = 152), we used a well-established experimental paradigm to examine the update of performance expectations in response to positive performance feedback, and its relation to depressive symptoms. In a 2x2 design, participants received either a negative mood induction, a cognitive immunisation manipulation, both, or no further manipulation.Results: Participants from all experimental groups updated their previous expectations significantly in line with positive performance feedback. However, depressive symptoms were a negative predictor of expectation update, and a moderation analysis indicated that this effect was particularly pronounced if participants underwent the negative mood induction. Conclusions: Consistent with previous work, depressive symptoms were related to reduced integration of positive information. Furthermore, our results suggest that in people with elevated levels of depression, the activation of negative mood can hamper learning from new positive experience.