An improved system for attaching a tub spout to the rough in water supply pipe or stub-out which typically extends out of a tub wall. The improved tub spout includes a vertical ring clamp inside the spout for receiving the stub-out. The stub-out passes through an aperture in the middle portion of the clamp and then into a tubular receiver. By tightening a screw associated with the clamp, the clamp is tilted to engage the stub-out. By further tightening of the screw, the stub-out is drawn into sealed engagement with the interior of the spout and the spout is drawn tightly against the tub wall.