A thermostatic mixing valve includes a mixing slide arranged between two seats for mixing fluids at different temperatures and capable of flowing between the mixing slide and the two seats, respectively, so as to supply a mixed fluid; and an axial thermal actuator arranged between the mixing slide and an absorption member sensitive to the temperature of the mixed fluid for creating a controlled movement of the position of the mixing slide between the two seats in order to supply the mixed fluid at a controlled temperature, where the absorption member includes one of the seats and is capable of moving in a direction that increases the distance between the seats when the mixing slide is bearing on the other seat so as to absorb an excess of axial movement of a rod of the absorption member due to excessive variation of the mixed fluid temperature.