Teachers’ beliefs significantly impact instructional design. Regarding teaching simulations and mathematical modelling with digital tools, teacher training should aim to strengthen constructivist (student-centred) and weaken transmissive (teacher-centred) beliefs. Using a pre- and post-test design, our quantitative intervention study (N = 204) investigates the change of above-mentioned beliefs of pre-service mathematics teachers participating in a university mathematics education course. Results reveal both significant effects in strengthening constructivist beliefs and in weakening transmissive beliefs that can be attributed to the intervention, whereas the reference group exhibited minimal non-significant changes. Finally, we discuss practical implications for research and teacher education.