In this article, we describe and evaluate an innovative pedagogical task designed to raise awareness of Global Englishes and to challenge standard language ideology in an English language classroom. The task encouraged the learning and debate of the controversial Speak Good English Movement, which campaigns for Singaporeans to use a "standard" form of English rather than the local variety, "Singlish". The debate was introduced as a Global Englishes-inspired multi-lesson task at a Japanese university with 108 students in four classes. Data were collected in the form of written reflections, in which learners stated their own positions and beliefs. Data indicated that the majority sided against the Speak Good English Movement, viewing Singlish as a legitimate variety of English with important cultural attributes, which contributed to a national identity. Results showed that the debate achieved the aim of encouraging students to critically reflect on standard language ideology in both English and Japanese, their mother tongue. Overall, the activity was successful in raising awareness of the diversity of English, and encouraging critical reflection on the complexities surrounding standard language beliefs. This was seen to be essential given the dominance of the "native" speaker episteme in Japanese language curricula.