use ExtUtils::MakeMaker; my $clean = {}; if (-f "Normalize.xs") { print STDERR "Making header files for XS...\n"; do "mkheader"; $clean = { FILES => 'unfcan.h unfcmb.h unfcmp.h unfcpt.h unfexc.h' }; } WriteMakefile( 'INSTALLDIRS' => $] >= 5.007 ? 'perl' : 'site', 'NAME' => 'Unicode::Normalize', 'VERSION_FROM' => 'Normalize.pm', # finds $VERSION 'clean' => $clean, );