The present disclosure relates to a stemless shoulder prosthesis comprising a fixation device for fixing the prosthesis to a resected humerus bone, the fixation device comprising a base portion (11) and anchoring means (12), the base portion (11) having a distal side adapted to contact a resection plane of the bone and a proximal side for carrying a humeral head (15). The anchoring means (12) are connected to the distal side of the base portion (11) and adapted to fix the prosthesis to the bone. The anchoring means (12) define a central axis (C) perpendicular to the distal side of the base portion (11) and a free central space (F) around the central axis (C). Further, the anchoring means (12) comprise wall sections (13) projecting from the base portion (11) substantially perpendicular to the distal side of the base portion (11). Each wall section (13) extends between an inner edge (I) and an outer edge (O). The wall sections (13) have a height measured from the distal side of the base portion (11), the height of each wall section (13) increasing from its outer edge (O) towards the inner edge (I), each wall section (13) having a minimum height at is outer edge (O) and a maximum height at its inner edge (I).
