A synchronous buck regulator controller is provided. The regulator controller includes switch control circuitry, an unloading event detection circuit, an inductor current detection circuit, and a synchronous switch control logic circuit. In operation, the regulator controller controls a main switch and a synchronous switch to control the buck regulation. The unloading event detection circuit is arranged to detect an unloading event, and to assert an unloading event signal if such an event is detected. The inductor current detection circuit is arranged to assert an inductor current detection signal if the inductor current is close to zero. The synchronous switch control logic circuit is arranged to block the synchronous switch from turning on if the unloading event signal is asserted and the inductor current detection signal is not asserted. However, if the inductor current detection signal is subsequently asserted while the unloading event signal is still asserted, the synchronous switch control logic circuit stops blocking the synchronous switch from turning on.