This study explores teacher perspectives on a government policy that seeks to integrate Indigenous knowledge into mainstream foreign language education in New Zealand schools. Based on in-depth interviews, the study found that language teachers generally support this educational change because trans/languaging involving English and te reo Maori (the Maori language) has become an ordinary practice in their teaching and school lives. However, foreign language teachers expressed a need for discipline-specific materials and professional development to help them integrate matauranga Maori (Indigenous knowledge of Maori) into their teaching. Their concerns can be understood as a lack of support in interpreting "what," "how," and "to what extent" the policy will be implemented. The study suggests using a decolonising approach to help teachers affirm the relevance of Indigenous knowledge in their discipline. It recommends that policymakers adopt a pluriversal stance to ensure that diverse knowledge systems can coexist and interact harmoniously rather than compete with one another in the new National Certificate of Educational Achievement (NCEA) curriculum.