diff --git a/lib/rubella/weighting/per_value.rb b/lib/rubella/weighting/per_value.rb
index 3da46a0..10456a9 100644
--- a/lib/rubella/weighting/per_value.rb
+++ b/lib/rubella/weighting/per_value.rb
@@ -15,7 +15,7 @@ module Rubella
       # every time value unit.
       #
       # @param input Rubella::Input An input object
-      # @return Array
+      # @return Rubella::Storage
       def parse input
         data = input.data
         # no data, no work