Bob Dylan fired back at a lawsuit filed in January by the estate of cowriter Jacques Levy in the wake of the legendary songwriter’s $300 million-plus sale of his catalog to Universal Music Publishing.

In a memo dated Tuesday, Dylan’s attorney wrote that the claims of Levy’s widow, who is seeking $7.25 million from the deal for songs cowritten with Dylan for the 1976 “Desire” album, are invalid because the songs were written under a work-for-hire arrangement that would garner Levy royalties but not a share of the copyrights. The news was first reported by The Hollywood Reporter.

“This lawsuit is an opportunistic attempt to rewrite a 45-year-old contract to obtain a windfall payment that the contract does not allow,” the memo’s preliminary statement reads. “The complaint should be dismissed with prejudice.”

It continues, “The agreement is a standard work-for-hire agreement between Dylan and Levy. It grants Dylan full ownership of the copyrights in the ten songs on which the two collaborated, making the songs Dylan’s ‘sole property’ and giving him the exclusive right to sell the copyrights.” According to the memo, Levy is entitled to 35% of the income from the songs.

As noted by THR, the memo also implies that Dylan fully owned his copyrights and maintained full publishing control, a rarity for songwriters that enabled him to regard cowriters as employees. It also states that since the Universal sale concluded in December, Dylan “no longer owns the copyrights or has any right to royalties from their exploitation,” and that he had preserved Levy’s right to 35% of the income. The memo concludes that Levy’s estate’s complaint is centered around an “impermissible double dip.”