diff --git a/CHANGELOG.md b/CHANGELOG.md
index d07a99f..0df1162 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Updated read_obs_sm_ASCAT_EUMET to work with both new and old filename formats. 
+
 ### Fixed
 
 ### Removed