diff --git a/app/models/spree/tax_rate.rb b/app/models/spree/tax_rate.rb
index 868b5e3a9f..bb200365e8 100644
--- a/app/models/spree/tax_rate.rb
+++ b/app/models/spree/tax_rate.rb
@@ -105,7 +105,7 @@ module Spree
         if default_zone_or_zone_match?(item.order)
           calculator.compute(item)
         else
-          # In this case, it's a refund.
+          # In this case, it's a refund (for instance offering a manual discount via an adjustment)
           calculator.compute(item) * - 1
         end
       else