The present disclosure relates to a lock (1) for a door comprising a housing (10) having a circular opening (11) in which a radial protrusion (12) is arranged, and a guide ring (20) arranged in the opening. The guide ring comprises a left locking means (22, 24) and a right locking means (22, 26). The radial protrusion is in a first position of the guide ring located between the left locking means and the right locking means on the guide ring. The guide ring is configured to be rotatable from the first position in a first direction (L) into a left locking position such that the protrusion engages with the left locking means so as to lock the guide ring relative to the housing, and configured to be rotatable from the first position in a second direction (R), opposite the first direction, into a right locking position such that the protrusion engages with the right locking means so as to lock the guide ring relative to the housing. A lock which after arrangement to a door may be configured for left or right hand operation is thereby provided.