Many English-medium instruction (EMI) classrooms in non-Anglophone countries adopt a multilingual stance, using English alongside the host country's local language(s). However, the perceptions of such multilingual practices held by students remain under-researched. Given many Asian countries' current drives to internationalize and diversify their student bodies, a clear understanding of international students' perspectives on multilingual EMI classrooms is long overdue. Through semi-structured interviews with international students from developing countries and the theoretical lens of language ideologies, this study investigates their perceptions of multilingual EMI classrooms in Taiwan. Most expressed a belief that their multilingual EMI classrooms, saturated with non-standard varieties of English, were not a legitimate pathway to acquiring their desired linguistic capital, i.e., standard English. These findings differ sharply from those of previous research, which has painted international students as holding positive attitudes towards English as a lingua franca (ELF). Moreover, the participants resisted the English-Mandarin translanguaging practices in their classrooms. As such, the findings highlight the need to understand the language ideologies of international students in Asia. Further investigation of learner resistance to multilingual EMI practices should also be conducted, with the wider aim of helping advanced English-language learners from developing countries accept different English accents, and accommodate ELF communication.