In template plugins, we often find double importing of the parent library: use Template::Plugin; use base qw( Template::Plugin ); Some of the plugins use 'base' [1] like this, and others use 'parent' (that seems to be what we should be using in this cases, as we are not ) [2]. [1] https://perldoc.perl.org/base [2] https://perldoc.perl.org/parent#HISTORY