We have been using PDF::API2 for some time and have been regularly getting these warnings: Subroutine PDF::API2::Resource::Font::Postscript::SEEK_SET redefined at C:/Perl/lib/Exporter.pm line 65. To avoid this, we have changed Line 46 of PDF::API2::Resource::Font::Postscript From IO::File to IO::File() and this resolves the problem. However, we would prefer not to diverge from CPAN where possible, so could this change please be added to your todo list. We experienced this problem running perl, v5.8.7 on Windows XP sp2. The problem appears to be a clash with certain modules. A test case is: package PDFAPI2Problem; use strict; use warnings; use Perl::Tidy; # other modules could also be used here to show problem use PDF::API2; 1; Any script using this module will throw the warning.