There is provided an unmanned aerial vehicle (UAV) with a flexible propeller guard. The flexible propeller guard may allow the UAV to be resiliently repelled from objects in the UAV's flight path, thereby protecting one or more of the UAV's propellers. The UAV may have foldable arms, movable between a deployed configuration and a stored configuration, and the flexible propeller guard may be used to restrain the folded arms in the stored configuration. The flexible propeller guard may be arranged so as to not interfere with the foldability of the arms.