Major policy changes make teachers reconsider how they teach. In Sweden, a new curriculum, a grading system, and national tests were introduced in science education in Year 6 (Y6) for the 2012/2013 academic year. After two years, the national tests were made voluntary, and they ended the following year. In this interview study, we investigate what implications these reforms had for teachers' teaching and assessment practices in science education. Interviews with 10 teachers over four subsequent years were analysed by applying Dewey's notion of habits in order to explore how teachers coordinate between their teaching habits and new policies. The result show that teachers work to adjust their teaching practices in order to; make teaching transparent, deal with the experience of increased levels of stress, develop professionally in collective practices, and reconsider the teaching content and methods. However, in the last round of interviews, it was evident that, after the tests were taken away, teachers downplayed the significance of the national tests as a factor that changed their teaching and changed what they consider as good science education.