The academic field of positive psychology has been rapidly growing in the past few years. Recently, a burgeoning interest in applying positive psychology to learning a second language (L2) has developed. One way to integrate positive psychology and L2 motivation is through showing relationships among key constructs from both disciplines. This paper explains and partially replicates positive psychology and motivational variables that elaborates on aspects of a positive L2 self-system. In previous studies, it has been theorized but empirically unknown if aspects of a positive L2 self-system are stable or malleable. This longitudinal study is the first to provide evidence for the stability and susceptibility to change for aspects of a positive L2 self-system in students in an educational context. After the presentation of the results, some implications based on the study are discussed.