When trying to pack a program that uses Mouse with pp, PAR::Packer will not pick up the Mouse::Meta::Method family. There is no use statement in Moose referencing these modules therefore Module::ScanDeps is not able to detect them. Workarounds: Add use statements for Mouse::Meta::Method::x in Mouse.pm or add special cases handling Mouse.pm to Module::ScanDeps. I'd suggest to change Mouse, because otherwise M::SD would need to be updated everytime the implementation of Mouse changes. Cheers, Christoph chris@jupiter:~$ perl -e 'package Test; use Mouse; has f => (handles => ["bar"]); print "1\n"' 1 chris@jupiter:~$ pp -o testmouse -M Mouse -e 'package Test; use Mouse; has f => (handles => ["bar"]); print "1\n"' chris@jupiter:~$ ./testmouse Could not load class (Mouse::Meta::Method::Delegation) because : Can't locate Mouse/Meta/Method/Delegation.pm in @INC (@INC contains: /tmp/par-chris/cache-b10cafda047140d830b82e388684527ff6d11363/inc/lib /tmp/par-chris/cache-b10cafda047140d830b82e388684527ff6d11363/inc CODE(0x92c6e90) CODE(0x92c7190)) at Mouse/Util.pm line 260.