Abstract Adjuncts differ from arguments by a number of properties, in particular i) optionality and ii) their island status, which renders them opaque for extraction of subconstituents. Conjuncts, too, are optional and forbid extraction. Starting from this basic observation, I demonstrate that islandhood is a direct consequence of optionality in every framework where extraction involves some dependency at the target site, for instance via feature checking. Given current generative assumptions about movement, it is thus unsurprising that optional constituents —- which I call ojuncts —- are islands.