Duplicate a material node setup with all the nodes it contains?

When I duplicate a node-based material, none of the other materials that the noodle references are duplicated, the copy still references the materials in the original nodes. I understand the logic of this, but it means that if I then edit the materials in the new noodle, the old noodle is altered too. Is there a way of duplicating a material noodle with everything included, so there’s no reference back to the original? (This would be the equivalent of append rather than link.)