The present invention relates to a composition based on poly(ether ether ketone) (PEEK) comprising poly(ether ketone ketone) (PEKK), characterized in that the poly(ether ketone ketone) (PEKK) comprises a mixture of terephthalic and isophthalic units, the percentage by weight of terephthalic units, with respect to the sum of the terephthalic and isophthalic units, being between 55 and 85%, limits included, and preferably between 55 and 70%, the said composition comprising between 1 and 40%, limits included, preferably between 5 and 40% and more preferably still between 10 and 30% by weight of PEKK, with respect to the total weight of the composition.