A cap for mounting on a damper tube of a vibration damper, having an outer shell region that is cylindrical at least in sections and at least one elastic spring tongue. At least one positively locking element is arranged on the spring tongue in order to produce a positively locking connection between the cap and a protective element of the vibration damper. The at least one spring tongue has a region which, in the non-mounted state of the cap, is set back inwardly in the radial direction with respect to the outer shell region. The set-back region has a spreading element, by way of which the spring tongue is spread outwardly in the radial direction during the mounting of the cap.