Vietnam universities have experienced remarkable changes brought about by their internationalization policies. The switch to English as a medium of instruction (EMI) for some academic programs was one of these critical changes. Literature has reported numerous issues related to EMI, including inadequate language proficiency of teaching staff. This paper looks at a qualitative research study on how a government university from Vietnam employs different strategies to enhance teachers' English proficiency. The study reveals that the introduction of new supporting systems, assessment bodies, recruitment criteria and institutional strategies on training, monitoring and motivation have created cultural change within the teacher community. This cultural change, which includes elements such as self-directed learning, peer learning, professionalism, and "open-to-change" attitudes, has been perceived by both leaders and teachers to be conducive to teachers' language learning. The findings presented in this paper seek to contribute to the formulation or adjustment of policies related to educational reforms, such as curriculum reform, teacher recruitment and teacher professional development in non-English-speaking countries.