Science policies and science studies largely share an understanding of scientific knowledge and objects as immutable mobiles. This article shows how the analysis of research assessment in a non-Anglophone country and its effects on social sciences can shed new light on this shared notion. The preference for immutable mobiles in assessment regimes pushes social scientists to publish in specialized, usually Anglophone journals, which can result in the attenuation of local relevance of the knowledge they produce and contribute to the performance (...) of globally converging societies. The author argues that the observed consequences for the social sciences in non-Anglophone countries underscore a larger problem with both the policy ideal and the science and technology studies idea of immutable mobiles on two counts: the relation of the social and natural sciences to society and the engagement of sciences with the multiplicity of societies as well as natures. (shrink)