require overload before using it This is detected when building with Test-Simple >= 1.3: . t/05_authz_runmodes.t .. 1..15 ok 1 - authz_runmodes() is consistent Error executing class callback in prerun stage: Undefined subroutine &overload::StrVal called at /build/libcgi-application-plugin-authorization-perl-0.07/blib/lib/CGI/Application/Plugin/Authorization.pm line 412.