While research has extensively studied the group of voluntary contributors and their motivation to participate in open source software (OSS) development, we lack an understanding of how firm-sponsored developers behave when they work for an OSS project. In specific, firm-sponsored developers may face identification conflicts arising from different social norms and beliefs inherent in both the organizational culture of their employing company and dominant OSS cultures. These conflicts may induce developer turnover intention towards the organization and the OSS community. This research seeks to identify identification-related determinants that drive turnover intention by surveying Linux kernel developers (N=321). This study finds, among others, that perceived external reputation of the employing organization reduces turnover intention towards the company while perceived own reputation dampens turnover intention directed towards the OSS community.