/* For platform which support the ISO C amendement 1 functionality we
support user defined character classes. */
# if defined _LIBC || WIDE_CHAR_SUPPORT
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included
+ before <wchar.h>. */
+# include <stdio.h>
/* Solaris 2.5 has a bug: <wchar.h> must be included before <wctype.h>. */
# include <wchar.h>
# include <wctype.h>