To what extent can teachers' involvement in knowledge-producing activities be enhanced through collaboration with researchers? This article reports on two teacher-researcher collaborative didactic development projects in Sweden and Finland. By using the theory of practice architectures, the aim is to explore how teachers' knowledge contribution and participation may be transformed through collaboration in two action research-based projects. Even though the practices of collaboration are different, one aiming for book production and the other for didactic development in the classroom, the findings regarding the teachers' professional transformation seem to have similarities. The norms of how teachers initially understand themselves are transformed through the collaboration. The teachers start out by stating that they feel unsure of their own capacity, but through collaboration they start to see themselves as knowledge producers when they understand the value of their contribution of knowing-in-action. The teachers' professional transformation is made possible through time given and the set-up of collaboration through dialogues. As the teachers develop agency in the collaborative process of producing knowledge with the researchers, the relationships of power and solidarity change. The findings contribute to the research field emphasising teachers' important role in knowledge production and practice development processes.