By 1963, Corman had produced several highly lucrative films based on Poe's work, but Lovecraft was not at that time a well-known author; according to Corman on the DVD making-of featurette, the studio forced him to name this movie after one of Poe's poems (and included a Poe epigraph in the credits) so that audiences would believe it to be another film based on Poe's writings.
By 1963, Corman had created several commercially successful films inspired by Poe's work, but Lovecraft was not yet a prominent author; as revealed in the DVD making-of featurette, the studio pressured him into titling this movie after one of Poe's poems (and included a reference to Poe in the credits) to make it appear as another film based on Poe's writings.