Teacher and librarian collaboration has relatively low priority in schools and in educational research. This is a paradox, as teachers and librarians share a common social and educational mandate of literacy education. The purpose of this article is to examine this paradox through exploring systemic contradictions in teacher and librarian collaboration within literacy education. Our data consist of discursive interaction between project leaders in an educational intervention project in Norway. The aim of the intervention is to develop teacher and librarian collaboration in two primary schools. Our analytical starting point is a critical conflict that occurred in one of the project leader meetings. The conflict arises from differing discourses of literacy education held by the local education authority and by the intervention project. We analyze how the project leaders respond to the conflict, how the conflict triggers new tensions and dilemmas within the project leader group and how the conflict creates obstacles to sustaining teacher and librarian collaboration in the project schools. We argue that sustainable change can be achieved by tracing conflicts, dilemmas and tensions to systemic contradictions within and between activity systems.