diff --git a/doc/whatsnew.rst b/doc/whatsnew.rst
index 7aaaa978a..67c6eef4f 100644
--- a/doc/whatsnew.rst
+++ b/doc/whatsnew.rst
@@ -9,13 +9,14 @@ Next release
 - Expand :doc:`repro` with sections on :ref:`repro-doc` and :ref:`versioning`, including :ref:`a list of external model names and ‘versions’ <model-names>` like “MESSAGEix-GLOBIOM 2.0” (:issue:`224`, :pull:`226`).
 - Update :doc:`/transport/index` (:pull:`213`).
 - Add "LED", "SSP4", and "SSP5" as values for the :program:`--ssp=…` option in :func:`.common_params` (:pull:`233`).
-- Fix and update :doc:`/api/tools-costs` (:pull:`219`, :pull:`206`, :pull:`221`)
+- Fix and update :doc:`/api/tools-costs` (:pull:`219`, :pull:`206`, :pull:`221`, :pull:`227`)
 
   - Fix naming of GDP and population columns in SSP data aggregation (:pull:`219`).
   - Edit inputs for storage, CSP, hydrogen, and industry technologies (:pull:`206`).
   - Replace solar and wind technologies with new ones (:pull:`206`).
   - Reorganize input files and incorporate `first_year.csv` data into `tech_map.csv` (:pull:`221`).
   - Reconfigure use and implementation of technology variants/modules to be more agnostic (:pull:`221`).
+  - Change cost decay to reach reduction percentage specified on the year 2100 (:pull:`227`).
 
 v2024.8.6
 =========