This study seeks to understand the possible extension of the classic marketing mix model towards sustainability. The purpose of this study is to investigate how internationally operating SMEs in the fashion industry can expand their marketing mix towards sustainability by including sustainability elements. The theoretical point of departure used in the study is the classical marketing mix model (4P) with extensions to the three sustainability elements derived from sustainability marketing literature. The study is carried out as a single case study of an SME in the fashion industry originated from Sweden which operates internationally. The obtained results show that the proposed extension of the classic marketing mix is highly relevant. In addition to this, another element is proposed within this extension. We introduce Public as the fourth extending element to the classic marketing mix model, as our findings show that this acts as a controllable key factor in educating consumers. Limitations and proposals for further research are finally presented under conclusion.