I recently received a request to peer review a paper for a specific issue of a journal, for which I had also submitted a paper. This is the third time a situation like this has occurred in the last 12 months. To be clear, the requests were withdrawn when I declared my own interest. My instinct is that the invitations to review should be declined/withdrawn in such circumstances. It seems to be unethical to proceed because the potential conflict of interest threatens the integrity of the peer review process. However I am now thinking about situations where the pool of suitable reviewers might be quite small, where some overlap is bound to occur. What are/should be the ethical guidelines where the pool of suitable reviewers is fairly small?