Newby-ish question -- SPARK v. Ada2005 problem

[Tim Rowe <spamtrap@tgrowe.plus.net>]

Looking at the tokeneer source, I find (in spark_io.adb, starting line 
123) the function:
   function File_Ref( File : File_Type) return Ada.Text_IO.File_Type
with (amongst others) the return statement:
       when NamedFile => return File.File.all;

Ada.Text_IO.File_Type is a limited type, and gnat informs me that this 
is illegal in Ada2005 because you can't copy objects of limited type 
(RM-2005 6.5(5.5/2), so there's a bit more to it). Gnat's recommended 
solution of using an access type instead is out if I want the code to be 
SPARK compliant, and (as a confessed neophyte) I can't see a way out of 
this other than hiding the code from SPARK (or using the -gnat95 
compiler flag, of course). Is there something obvious that I'm missing?

Thanks in advance!