diff --git a/Installation/CHANGES.md b/Installation/CHANGES.md
index da44a890a15..1ea699331b5 100644
--- a/Installation/CHANGES.md
+++ b/Installation/CHANGES.md
@@ -1,5 +1,14 @@
 Release History
 ===============
+
+[Release 5.5](https://github.com/CGAL/cgal/releases/tag/v5.5)
+-----------
+
+### [Polygon Mesh Processing](https://doc.cgal.org/5.5/Manual/packages.html#PkgPolygonMeshProcessing)
+
+-   Added the function `CGAL::Polygon_mesh_processing::tangential_relaxation()`, which
+applies an area-based tangential mesh smoothing to a surface triangle mesh vertices.
+
 [Release 5.4](https://github.com/CGAL/cgal/releases/tag/v5.4)
 -----------