A composition including 2,4,4,4-10-tetrafluorobut-1-ene and cis-1,1,1,4,4,4-hexafluorobut-2-ene, and also the use thereof in particular as a heat transfer fluid. The composition may include: from 1% to 99% of 2,4,4,4-tetrafluorobut-1-ene and from 1% to 99% of cis-1,1,1,4,4,4-hexafluorobut-2-ene; preferably from 5% to 70% of 2,4,4,4-tetrafluorobut-1-ene and from 30% to 95% of cis-1,1,1,4,4,4-hexafluorobut-2-ene; preferably from 20% to 65% of 2,4,4,4-tetrafluorobut-1-ene and from 35% to 80% of cis-1,1,1,4,4,4-hexafluorobut-2-ene; preferably from 25% to 60% of 2,4,4,4-tetrafluorobut-1-ene and from 40% to 75% of cis-1,1,1,4,4,4-hexafluorobut-2-ene; preferably from 28% to 51% of 2,4,4,4-tetrafluorobut-1-ene and from 49% to 72% of cis-1,1,1,4,4,4-hexafluorobut-2-ene.