Summary: In Montenegro, there has been a deep divide between those who seek the independence of Montenegro and those who oppose it. It is well known that there is a correlation between the ethnic identity and the attitude towards this issue. While one tends to assume that the former determines the latter, this article would argue that this assumption does not hold for Serbs. To do so, this article analyzes the re-definition of ethnic identity in Montenegro. In particular, a significant number of those who now regard themselves as "Serb" did not indeed do so only twelve years ago. This suggests that the assumption discussed above is wrong and the causal relations run in the opposite direction: they re-defined themselves as "Serb" because they support the maintenance of the union with Serbia.