Grounded in career construction theory, we proposed that proactive personality (a disposition that drives people to focus on the future) influences career adaptability (the attitudes and behaviours that people use to adapt to work), which in turn influences career exploration (purposive cognition and behaviour to seek information for self-career advancement). However, psychological safety as a boundary condition may affect career adaptability's relation to career exploration. Hence, this study examined whether students' psychological safety moderates career adaptability's mediating effect on the relationship between proactive personality and career exploration. A total of 288 students who completed internships at Taiwanese sports centres or fitness clubs participated in this research. The results indicate that interns' psychological safety, functioning as a moderator, intensifies proactive personality's indirect effect on career exploration through career adaptability. The implications of this finding for students' career counselling are discussed.