The right of a de facto couple to adopt a child has been upheld by the High Court in a judgement delivered on Thursday.
The case involved a woman and her de facto partner who applied to adopt a child born to the woman before the current relationship began.
The Adoption Act refers only to applications made by two spouses jointly.
Lawyers for the Crown told the High Court it was up to Parliament to decide whether that should be extended to include de facto couples.
However the High Court Justices pointed to various pieces of legislation, including the Companies Act, in which the word spouse includes de facto partners.
They acknowledged that giving spouse a meaning beyond "married couple" opens the door for adoption applications from other other types of couples.
But they said those applications would not necessarily achieve the same result.