Also be aware that the list of core modules can vary between versions. I've never personally encountered a problem with this; however, if it is an issue for you, you can specify a range of valid versions with use and no.

Version too old:

$ perl -v | head -2 | tail -1
This is perl 5, version 18, subversion 0 (v5.18.0) built for darwin-th
+read-multi-2level
$ perl -e 'use 5.020; no 5.024'
Perl v5.20.0 required--this is only v5.18.0, stopped at -e line 1.
BEGIN failed--compilation aborted at -e line 1.
$
[download]

Version too new:

$ perl -v | head -2 | tail -1
This is perl 5, version 24, subversion 0 (v5.24.0) built for darwin-th
+read-multi-2level
$ perl -e 'use 5.020; no 5.024'
Perls since v5.24.0 too modern--this is v5.24.0, stopped at -e line 1.
BEGIN failed--compilation aborted at -e line 1.
$
[download]

Version just right (Goldilocks zone):

$ perl -v | head -2 | tail -1
This is perl 5, version 22, subversion 0 (v5.22.0) built for darwin-th
+read-multi-2level
$ perl -e 'use 5.020; no 5.024'
$
[download]