The asynchronous circuit includes a fork having at least two branches, each branch being connected to a logic gate so that the logic gate receives as input a branch-ending signal. It further includes a circuit for branching the branch-ending signal at the level of each logic gate to form a branched signal, and a blocking circuit comprising a Muller gate and receiving as input at least one branched signal, the blocking circuit being configured to prevent the propagation of an output signal when the branch-ending signals are in different logic states.