An elastomeric mixture comprises at least: one diene elastomer/polylactide copolymer A1 comprising a polylactide block PLLA or PDLA, where appropriate one or more other polylactide blocks which are all PLLA when the first block is PLLA or which are all PDLA when the first block is PDLA, the mass percentage of the polylactide block(s) being between 10% and 50% by weight relative to the weight of the copolymer A1, and a diene elastomer/polylactide copolymer B1 the mass percentage of the polylactide block(s) in said copolymer B1 being between 10% and 50% by weight relative to the weight of the copolymer B1, or a polylactide B2, or a mixture of said copolymer B1 and of said polylactide B2, the names PLLA and PDLA denoting a chain consisting of units of formula (I) —[CH(CH3)—C(O)—O]— (I), of which at least 70% by weight are, respectively, of L and D configuration.