Github API Cannot Set User Emails

I'm trying to synchronize user names and primary emails with AD via the Github API. I make a call to /user/emails using an oAuth token with scope user:email and I get back their primary email. I then try to use PATCH /user per this doc with the payload:

{
   email: newemail@ourcompany.com
}

And I get back a 404.

Is this the correct method to set the primary emails for users?