The inability to differentiate skeletal remains belonging to the ferret from those of its wild ancestor, the European polecat, presents a particular challenge for zooarchaeologists which currently hinders a better understanding of ferret domestication history. Using a geometric morphometric approach on the mandible, this study provides a new method to distinguish the two forms. Despite a small sample size and some overlap in the dataset, this method allowed the identification of a (post)medieval specimen from Mechelen (Belgium) as a wild polecat. Results demonstrate that ferrets can largely be distinguished from polecats based on mandibular morphology.