A hair-cutting unit for a shaving device, the hair-cutting unit including a hair-cutting element and a telescopic drive-shaft. The drive-shaft comprises a first shaft-segment, which is in telescopic engagement with a co-rotating second shaft-segment, which itself is in telescopic engagement with a co-rotating third shaft-segment. A spring presses the first telescopic shaft-segment and the third telescopic shaft-segment away from one another. In an embodiment, the first and second telescopic shaft-segments are in mutual tillable engagement, and/or the second and third telescopic shaft-segments are in mutual tillable engagement.