The changing sociolinguistic landscape of English with novel uses and users calls for adjustment of the existing Anglocentric English Language Teaching practices, thereby encouraging paradigm shifts, including Teaching English as an International Language (TEIL). To this end, for a PhD study, an EIL-oriented course was designed and implemented, aiming at promoting understanding and awareness of sociolinguistic realities and the complexity of English, changing attitudes towards diversity, and enhancing proficiency. Later, a course evaluation with 53 preparatory English majoring participants (F = 41, M = 12) was conducted to find out whether it could achieve these designed outcomes. The data was drawn in a mixed-method way from a pre and post-treatment questionnaire and focus-group interviews. The participants' understanding and awareness improved, and most took positive attitudes towards EIL, and their listening, interaction, and critical thinking skills broadened. Yet, it was also found that because some still regarded Americans and the British as the custodians, they viewed diversity as corruption, thereby tending to see Standard English as the only instructional variety to be brought to the classroom. In the end, ways to turn the classroom into an EIL-sensitive, interactive, and authentic atmosphere to give students a real reason to communicate, hear, and respect differences at both linguistic and cultural levels were suggested.