We present the results of a prospective observational study aimed to understand whether there is a relationship between personality traits (i.e., agreeableness, conscientiousness, extroversion, neuroticism, and openness) and the performance of undergraduates in Computer Science while accomplishing bug fixing. We involved 62 undergraduates, who took part in eight laboratory sessions. The experimental sessions took place over a period of seven weeks. In each session, the participants were asked to fix bugs either in a C or in a Java program. We collected a relevant number of observations (496, in total) so making our study the largest (quantitative) one on the impact of personality on individual performance while executing an SE task. We observed that the lower the neuroticism level of a student, the better his/her performance in fixing bugs is.