Regular arrangement of nanocrystalline domains can introduce interference effects which alter considerably the powder diffraction pattern. Role of nanocrystal alignment (local texture) and mutual positioning are different, with the latter much more effective in controlling the interference effect. While it is demonstrated that these effects are unlikely to be observed on a conventional laboratory instrument, coherence conditions available at modern synchrotron radiation beamlines might support further investigations of interference in systems made of very fine nanocrystals.