Studies of English as a lingua franca (ELF) in higher education institutions have focused on students' learning outcomes and intelligibility in ELF, but little attention has been given to local students' resistance to the use of ELF. Utilising the concept of language ideology and interactive regimes, I demonstrate the tensions and dilemma arising from the choice between English and the local language in the international university context where English has been adopted as an official language. This paper focuses on a specific institution in Korea, but the findings have broader implications for higher education's pursuit of internationalisation.