An electronic deadbolt includes a housing, a deadbolt configured to extend or retract from the housing, and a drive system disposed at least partially within the housing. The drive system includes an electric motor and a leadscrew coupled between the electric motor and the deadbolt. The leadscrew is rotatable about a longitudinal axis so as to dive movement of the deadbolt. The drive system also includes a flexible coupling disposed between the electric motor and the leadscrew and is configured to absorb torsional loads generated by the movement of the deadbolt.