Compositions comprising collagenase G and collagenase H (in a ratio between 1:2.5 and 1:3.5), optionally formulated in hydrogels, and its uses as medicament for the treatment of diseases involving alterations of collagen, such as fibromatosis, palmar Dupuytren's contracture, La Peyronie's disease, Ledderhose's disease or retractable scars.