Close #3205
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 766cb31..5c233ef 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -306,6 +306,7 @@
       -  Added a ``$reset`` parameter to method ``initialize()``.
       -  Removed method ``clean_file_name()`` and its usage in favor of :doc:`Security Library <libraries/security>`'s ``sanitize_filename()``.
       -  Removed method ``mimes_types()``.
+      -  Changed ``CI_Upload::_prep_filename()`` to simply replace all (but the last) dots in the filename with underscores, instead of suffixing them.
 
    -  :doc:`Calendar Library <libraries/calendar>` changes include: