Warlpiri communities in Australia’s Northern Territory (NT) have long advocated for the inclusion of Warlpiri language, values and knowledge in their government-run schools. After the first bilingual programs were established in the NT in the 1970s, educators and community members from four Warlpiri communities formed a professional network known as the Warlpiri Triangle, a platform for meetings and professional development focusing on teaching and learning in and of Warlpiri language in schools. On these platforms, educators have consistently articulated the goal of the Warlpiri programs as maintenance of Warlpiri pirrjirdi, ‘strong Warlpiri language’. In this paper we seek to explore the development, refinement and consolidation of a consensual ideology around teaching and learning of and in Warlpiri pirrjirdi, ‘strong Warlpiri language’ that has informed Warlpiri language-in-education management. We analyse interviews with five Warlpiri educators at Yuendumu school in 2018/9 and a body of grey literature from four decades of Warlpiri educator professional development activities that has been less widely acknowledged and visible in local education policy discourse. We draw on the theoretical concept of communities of practice to understand the ways in which Warlpiri educators negotiate ideological and implementational spaces for inclusion of Warlpiri language teaching in the context of an ambivalent language-in-education policy environment. The results of this study exemplify the reiteration and reproduction of language-in-education goals through a community of practice in a sustained arena of action, the Warlpiri Triangle. The findings render more visible the vital efforts of Warlpiri educators and their professional networks in shaping language-in-education policy and practice to realise community aspirations of Warlpiri language maintenance in the school context.