Quick changer for coupling and uncoupling attachments to and from a dipper arm of an earth-moving machine , wherein the quick changer has a quick-changer frame which is preferably in the form of a housing and has on its front side two laterally mutually spaced claw-shaped catch hooks with a forwardly facing opening for engaging on a shaft on the attachment and on the rear side of which, i.e. on an outer side opposite the openings of the catch hooks , two locking bolts (38a, 38b; 50a, 50b) which are arranged next to one another are accommodated in a retractable and extendable manner, and wherein the quick-changer frame comprises a first single-acting or double-acting hydraulic linear actuator system (18a, 40a, 45a, 18b, 40b, 45b; 48a, 45a, 48b, 45b), via which the locking bolts (38a, 38b; 50a, 50b) can be moved linearly via hydraulic pressure between a locked position and an unlocked position for locking and unlocking on the attachment , wherein the locked position is displaced rearwardly relative to the unlocked position and the unlocked position is displaced forwardly relative to the locked position, and wherein a securing device is provided in order to prevent, in the event of insufficient locking of the locking bolts (38a, 38b; 50a, 50b), a drop of the attachment from the quick changer , and a separate, hydraulically driven actuating device (19, 33, 34, 46; 69; 79, 73; 83) for actuating the securing device, characterized in that the securing device comprises at least one securing claw (30; 60; 70; 80) which is suitable for gripping the shaft and which is pivotably arranged on the front side of the quick-changer frame about an axle parallel to the axis of the shaft , wherein the securing claw (30; 60; 70; 80) is pivotable via the actuating device (19, 33, 34, 46; 69; 79, 73; 83) at least from its release position in which it lets go of the shaft into its engagement position in which it grips the shaft . the quick changer has a quick-changer frame which is preferably in the form of a housing and has on its front side two laterally mutually spaced claw-shaped catch hooks with a forwardly facing opening for engaging on a shaft on the attachment and on the rear side of which, i.e. on an outer side opposite the openings of the catch hooks , two locking bolts (38a, 38b; 50a, 50b) which are arranged next to one another are accommodated in a retractable and extendable manner, and wherein the quick-changer frame comprises a first single-acting or double-acting hydraulic linear actuator system (18a, 40a, 45a, 18b, 40b, 45b; 48a, 45a, 48b, 45b), via which the locking bolts (38a, 38b; 50a, 50b) can be moved linearly via hydraulic pressure between a locked position and an unlocked position for locking and unlocking on the attachment , wherein the locked position is displaced rearwardly relative to the unlocked position and the unlocked position is displaced forwardly relative to the locked position, and wherein a securing device is provided in order to prevent, in the event of insufficient locking of the locking bolts (38a, 38b; 50a, 50b), a drop of the attachment from the quick changer , and a separate, hydraulically driven actuating device (19, 33, 34, 46; 69; 79, 73; 83) for actuating the securing device, characterized in that the securing device comprises at least one securing claw (30; 60; 70; 80) which is suitable for gripping the shaft and which is pivotably arranged on the front side of the quick-changer frame about an axle parallel to the axis of the shaft , wherein the securing claw (30; 60; 70; 80) is pivotable via the actuating device (19, 33, 34, 46; 69; 79, 73; 83) at least from its release position in which it lets go of the shaft into its engagement position in which it grips the shaft . <EOS>