Abstract: A connection between a fluid line and a connecting element, in which at one end the line has an insertion part, and the connecting element is provided with an bore for accommodating the insertion part of the line, in which the line is provided with a locking shoulder, and in which the connecting element is designed to accommodate a locking element, which locking element when fitted covers the locking shoulder of the line, so that the insertion part of the line is locked in the bore of the connecting element, in which the bore, viewed in the insertion direction of the insertion part has a first part with a first diameter and connecting thereto a second part with a second diameter which is smaller than the first diameter.