A headphone (1) comprising a first earphone (2) and a headband (3) to be arranged around the head of a user. The headband (3) comprises a first headband part (4) and a second headband part (5), that are telescopically connected, so that the length of the headband (3) can be adjusted in a longitudinal direction (Y). The first headband part (4) comprises an inner wall (9) with a protruding longitudinal first rib (8), which first rib (8) has a first rib sidewall (35) with a first rib protrusion (33) and a second opposite rib sidewall (36) with a second rib protrusion (34). The second headband part (5) comprises an outer wall (7) with a first longitudinal groove (6), which first groove (6) has first groove sidewall (20) with a first groove protrusion (22) and a second opposite groove sidewall (21) with a second groove protrusion (23). The first rib (8) is received in the first groove (6), and the first and second rib protrusions (33, 34) and the first and second groove protrusions (22, 23) defines small well-defined contact areas between the rib sidewalls (35, 36) and the groove sidewalls (20, 21).