Problem with portupgrade and py27-tkinter

[Montgomery-Smith, Stephen]

I have both py27-tkinter and py36-tkinter installed.  When I do 
portupgrade, it tries to upgrade py27-tkinter to py36-tkinter:

portupgrade -a
[Reading data from pkg(8) ... - 1061 packages found - done]
** Detected a package name change: py27-tkinter 
(x11-toolkits/py-tkinter) -> 'py36-tkinter' (x11-toolkits/py-tkinter)
--->  Upgrading 'py27-tkinter-2.7.16_6' to 'py36-tkinter-3.6.8_6' 
(x11-toolkits/py-tkinter)
etc, etc.