Even better is to put your config in a module, with each configuration option being a subroutine declared with an empty prototype (and thus considered by the compiler for inlineing). Example:

package My::Config;

sub VARIABLE1 () { 'variable value' }
sub VARIABLE2 () { [ 'a', 'b', 'c' ] }

1;
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You call it like this:

use My::Config;
my $var1 = My::Config::VARIABLE1;
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Which, if you put this through B::Deparse, will look like:

use My::Config;   # Actually, 
my $var = 'variable value';
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And is thus gives you the advantages of a hard-coded variable without the icky problem of maintainability.

Note, though, that strict won't catch undeclared variables with full package names, so if you do:

my $var1 = My::Config::VAR1;
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strict will happily allow it.