Can't select "their" as gender/pronoun when signing up - "Invalid gender"

[andc]

Don't have the exact error text sorry, but it was a javascript alert saying something along the lines of "invalid gender" if I selected "their". selecting "her" or "his" worked fine.

[Chris is me]

Can we make pronouns changeable after accounts are created? Many reasons why this is a good idea, but mostly because I had to pick the wrong pronoun when registering for the beta and I'd like to change that once the right one is available.