In 2015, for its 55th anniversary, the film went through an extensive 4K digital restoration, from a 6K scan of the 1991 reconstruction of the film, in which Robert A. Harris served as consultant. The 2015 restoration is 12 minutes longer and the original, 6-channel audio track was also remixed and remastered in 7.1 surround sound. The film was re-released to Blu-ray Disc on October 6, 2015, featuring a 1080p transfer of the 2015 restoration in 2.20:1 aspect ratio and 7.1 DTS-HD Master Audio surround sound. Special features include a featurette on the 2015 restoration, a 2015 interview with Kirk Douglas, and several features from the Criterion Collection DVD.