The term “case study” is not used consistently when describing studies and, most importantly, is not used according to the established definitions. Given the misuse of the term “case study”, we critically analyse articles that cite case study guidelines and report case studies. We find that only about 50% of the studies labelled “case study” are correctly labelled, and about 40% of studies labelled “case study” are actually better understood as “small-scale evaluations”. Based on our experiences conducting the analysis, we formulate support for ensuring and assuring the correct labelling of case studies. We develop a checklist and a self-assessment scheme. The checklist is intended to complement existing definitions and to encourage researchers to use the term “case study” correctly. The self-assessment scheme is intended to help the researcher identify when their empirical study is a “small-scale evaluation” and, again, encourages researchers to label their studies correctly. Finally, we develop and evaluate a smell indicator to automatically suggest when a reported case study may not actually be a case study. These three instruments have been developed to help ensure and assure that only those studies that are actually case studies are labelled as “case study”. © 2022 The Author(s)