diff --git a/CHANGELOG.md b/CHANGELOG.md
index f94066d3..b772640d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,7 @@ change warranting a new major release:
 
 - Remove 2 TCS threads.
 - Move low level polling into ACS PST, move high level device handlers into TCS system task.
+- Igrf13 model vector now outputs as uT instead of nT
 
 # [v1.27.1] 2023-02-13