With the globalization of the English language, Global Englishes (GE) is a growing research paradigm with numerous pedagogical implications for those learning and teaching English. The study reported here provides insights on pre- and in-service Teaching English to Speakers of Other Languages (TESOL) practitioners' perceptions of Global Englishes Language Teaching (GELT) (Galloway & Rose, 2015; Rose & Galloway, 2019), which aims to make TESOL classrooms more reflective of learners' needs in today's globalized world, where multilingualism is the norm and English functions as a lingua franca. Interviews (n=5) with those taking a GE course on an MSc TESOL programme at a Russell Group university in the UK were triangulated with a survey among the wider programme (n=66). The study reveals that curriculum innovation is complex, particularly when it requires a conceptual transition, and practitioners need time and support to implement change. Furthermore, it was clarified that GE has made little headway into 'traditional' TESOL classrooms, which remains biased towards 'native' English norms.