Fixing Papertrail "Tried to load unspecified class: ActiveSupport::TimeWithZone"

Ran into this error when doing reify on a papertrail version. Couldn't easily find a solution online, so thought I'd post it for future reference. Just add this to your application.rb:

config.active_record.yaml_column_permitted_classes = [ActiveSupport::TimeWithZone, ActiveSupport::TimeZone, Time, Date]