Coupling element for suspending a sliding door leaf from a roller body of a sliding door assembly, wherein said roller body for this purpose comprises a downwardly hanging shaft having a widened section at the bottom, the coupling element comprising - a fastening body for fastening the coupling element to the sliding door leaf, having a fitting cavity for fitting the shaft with its widened section into the fastening body, comprising an insertion opening through which the widened section is fittable in the fitting cavity and a shoulder which extends next to the insertion opening, underneath which shoulder the widened section is at least partially fittable via the insertion opening, in order for said widened section to engage underneath said shoulder; - a retaining element which is arranged at the bottom of the fitting cavity in such a way that it is hingeable about a substantially horizontal hinge pin between an upper position in which it prevents the moving of the widened section in and out of the insertion opening and a lower position in which it opens the insertion opening for the insertion of the widened section; - a resilient element which is arranged under the retaining element and exerts a force on the retaining element which pushes the retaining element into its upper position; characterized in that the coupling element further comprises - a releasing element which is displaceable between a first position in which the retaining element is hingeable about its hinge pin and a second position for retaining the retaining element in its lower position; wherein the hinge pin about which the retaining element is hingeably arranged is arranged on the side of the shoulder opposite to the insertion opening, and in that the releasing element is arranged above the retaining element and is adjustable to its first position and to its second position. - a fastening body for fastening the coupling element to the sliding door leaf, having a fitting cavity for fitting the shaft with its widened section into the fastening body, comprising an insertion opening through which the widened section is fittable in the fitting cavity and a shoulder which extends next to the insertion opening, underneath which shoulder the widened section is at least partially fittable via the insertion opening, in order for said widened section to engage underneath said shoulder; - a retaining element which is arranged at the bottom of the fitting cavity in such a way that it is hingeable about a substantially horizontal hinge pin between an upper position in which it prevents the moving of the widened section in and out of the insertion opening and a lower position in which it opens the insertion opening for the insertion of the widened section; - a resilient element which is arranged under the retaining element and exerts a force on the retaining element which pushes the retaining element into its upper position; characterized in that the coupling element further comprises - a releasing element which is displaceable between a first position in which the retaining element is hingeable about its hinge pin and a second position for retaining the retaining element in its lower position;