The Dzyaloshinskii-Moriya interaction (DMI), which is essential for the stabilization of topologically nontrivial chiral magnetic textures such as skyrmions, is particularly strong in heterostructures of ultra-thin magnetic materials and heavy elements. We explore by density-functional theory calculations the possibility to modify the magnetic properties at Co/Pt interfaces with chemical disorder. In these systems, we find a particular robustness of the DMI against intermixing. Upon dusting the interface with a third element (all 4d transition metals and B, Cu, Au and Bi), a strong reduction of the DMI is predicted. This opens up possibilities to tune the DMI through the degrees of intermixing and dusting.