The η-phase field of the Cu-In system is unusually rich and shows wealth of phases that are all related to the B8 (NiAs/Ni2In) type. Previous electron diffraction work has revealed extensive super structure ordering; in this study, we report single crystal diffraction experiments on high-quality samples of two of the phases in the system, ht1-Cu 5 In 3 and ht2-Cu 5 In 3 . Both these phases constitute super structures, caused by the ordering of interstitials. The structure ht2-Cu 5 In 3 is a relatively simple structure with a bidimensional modulation but where only first order satellites are visible, indicating incomplete order whereas ht1-Cu 5 In 3 displays many high order satel- [a]