I'm making a package for graphics/p5-Image-EXIF

The distribution file is: Image-EXIF-1.00.3.tgz
(It's located at 
http://search.cpan.org/CPAN/authors/id/C/CC/CCPRO/Image-EXIF-1.00.3.tgz)

During build package source looks for: Image-EXIF-1.00.3.tar.gz, but does 
not find it because the extension of the needed file is .tgz instead of 
tar.gz

Is there an option to tell pkgsrc to look for $distname.tgz file instead of 
$distname.tar.gz ?
                    Thanks, Roman Kulik