How to mount /proc/sys/fs/binfmt_misc ?

OK, I've been struggling with this (off and on) since Tuesday, and I give up.
Since going from 2.4.3-pre4 to 2.4.2-ac20 I have been unable to use binfmt_misc.
Thanks to a hint from Michael Meissner, I found a mention in the release notes
for 2.4.2-ac12 that binfmt_misc should be mounted separately.  However, I still
have a problem.

  The release notes specify this:

     mount -t binfmt_misc none /proc/sys/fs/binfmt_misc

but this doesn't work because

     mount: mount point /proc/sys/fs/binfmt_misc does not exist

And if I try to mkdir -p /proc/sys/fs/binfmt_misc with /proc mounted I get

     mkdir: cannot create directory `/proc/sys/fs/binfmt_misc': No such file or
directory

which makes sense, I guess, because proc isn't a "real" filesystem.  So how do I
get binfmt_misc mounted?

Wayne