Abstract This paper considers the utilisation, appropriation, and renegotiation of colonial knowledge in the form of land and population registers by local litigants in eighteenth-century Dutch colonial Sri Lanka. Using a database compiled from thirty-three civil court cases held before the Landraad rural council of Colombo, I highlight how Lankan litigants frequently used the colonial thombo registers as evidence to have their property recognised. Moreover, I show that these registers were not just utilised but also altered through this process, particularly through the promotion of alternative knowledge in the form of local witness testimonies and ola palm leaf documents during court cases. I subsequently argue that we should reconsider how we view colonial knowledge. Rather than a static, top-down view from a foreign bureaucracy on a colonised society, this knowledge could be appropriated and even altered through the acts of local agents, in turn changing what was known by the colonial state and thus creating a “looping effect” of knowledge production.