Fixed expressions pose numerous comprehension and equivalence problems both for users and translators. This article analyses seven translation programmes that have been developed in the last thirty years for automatic translation of texts without the intervention of human translators. The programmes are applied to a series of fixed expressions extracted from the Spanish novel El capitán Alatriste by A. Pérez‑Reverte. The results are compared with the manual translation of the French version as well as the solutions presented by two bilingual Spanish‑French dictionaries. We conclude that developers of automatic translation programmes need to elaborate this problem in greater depth in order to produce better founded linguistic resources for enhancing the quality of the translations.