References greyed out in VBA window

I needed to add some references in an Access 2013 code module. Going to Tools, I found the References item greyed out. Research led to this article with a registry key to enable References:

[HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Access\Security]
"AccessVBOM"=dword:00000001

Note that I am an admin on this machine, running Office 2013 (hence the "15.0") and need VBA in Access. You'll need to modify the above to your needs.