Specific heat of Pu doped with Am was studied for several Am concentrations (8-20 per cent) ensuring the delta-Pu fcc structure. The results reveal that the γ-value of the low temperature specific heat is lower than originally assumed (γ about 35 - 55 mJ/mol K2 can be deduced for Pu-8 per cent Am) and does not increase with the Am-induced lattice expansion. The findings can be taken as an indication of the absence of the Pu-5f states at the Fermi level. ; JRC.E.6-Actinides research