A quick coupler for coupling a tool like for example a scoop, shell grab or demolition tongs to a tool guide such as an excavator arm or the like, including a coupling receptacle for receiving a first locking part and a locking receptacle for receiving a second locking part, wherein to the coupling receptacle a self-locking securing element is associated for catching and/or securing the first locking part in the coupling receptacle, and to the locking receptacle a pressure-medium-actuatable locking element is associated for locking the second locking part in the locking receptacle. The self-locking securing element of the coupling receptacle likewise is actuatable by the pressure circuit.