Winglet linked to a wing of an aircraft and equipped with a configuration changing device, said winglet being configured to be deformed elastically between a first configuration in the absence of an activation loading and a second configuration in the presence of an activation loading, said configuration changing device comprising: - an activation mechanism configured to occupy a non-activated state in which it exerts no loading on the winglet and an activated state in which it exerts the activation loading so as to deform the winglet from the first configuration to the second configuration, and - a holding mechanism configured to hold the winglet in the second configuration, the holding mechanism comprising: - at least one blocking cable which has a first anchoring point (42.1) linked to the winglet, - at least one blocking system passed through by the blocking cable and configured to occupy a free state in which it does not immobilize the blocking cable and a blocked state in which it immobilizes the blocking cable, - the first anchoring point (42.1) and the blocking system being positioned in such a way that the blocking cable stretched between the first anchoring point (42.1) and the blocking system is configured to hold the winglet when the latter occupies the second configuration, characterized in that the blocking system comprises a tank containing a material having a melting point and configured to occupy a solid state, when the temperature of the material is lower than the melting point, in which it immobilizes the blocking cable which corresponds to the blocked state of the blocking system and a liquid state, when the temperature of the material is higher than the melting point, in which it does not immobilize the blocking cable and allows the displacement thereof which corresponds to the free state of the blocking system. - an activation mechanism configured to occupy a non-activated state in which it exerts no loading on the winglet and an activated state in which it exerts the activation loading so as to deform the winglet from the first configuration to the second configuration, and - a holding mechanism configured to hold the winglet in the second configuration, - at least one blocking cable which has a first anchoring point (42.1) linked to the winglet, - at least one blocking system passed through by the blocking cable and configured to occupy a free state in which it does not immobilize the blocking cable and a blocked state in which it immobilizes the blocking cable, - the first anchoring point (42.1) and the blocking system being positioned in such a way that the blocking cable stretched between the first anchoring point (42.1) and the blocking system is configured to hold the winglet when the latter occupies the second configuration, characterized in that the blocking system comprises a tank containing a material having a melting point and configured to occupy a solid state, when the temperature of the material is lower than the melting point, in which it immobilizes the blocking cable which corresponds to the blocked state of the blocking system and a liquid state, when the temperature of the material is higher than the melting point, in which it does not immobilize the blocking cable and allows the displacement thereof which corresponds to the free state of the blocking system.