Learning to program requires perseverance, practice, and the mindset that programming skills are improved through these activities (i.e., that everyone has the potential to become good at programming). In contrast to an entity mindset, individuals with an incremental mindset believe that ability is malleable and can be improved with effort. Prior research shows that an incremental mindset can be promoted through interventions and that, as a result, individuals report increased belief in the value of effort. Although this is encouraging, the majority of research targets a general mindset, and so little work exists exploring the effect of this construct in the programming domain. The present study (N = 47) used a programming activity to test the effect of an incremental mindset intervention on participants' beliefs, effort, programming behaviors, and performance in an experimental study. The intervention was successful. Compared to the control group, the experimental group shifted significantly more toward an incremental mindset, which resulted in beneficial behaviors related to effort, namely higher time on task and more program creation and modification actions. These positive behaviors, however, did not translate to improvements in programming performance. We speculate the reason for this latter finding may be related to the need for additional domain-based support.