diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 2b0f51b..cb955e8 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -12,6 +12,7 @@
 
 -  Fixed a bug (#4212) - :doc:`Query Builder <database/query_builder>` method ``count_all_results()`` could fail if an ``ORDER BY`` condition is used.
 -  Fixed a bug where :doc:`Form Helper <helpers/form_helper>` functions `set_checkbox()`, `set_radio()` didn't "uncheck" inputs on a submitted form if the default state is "checked".
+-  Fixed a bug (#4217) - :doc:`Config Library <libraries/config>` method ``base_url()`` didn't use proper formatting for IPv6 when it falls back to ``$_SERVER['SERVER_ADDR']``.
 
 Version 3.0.3
 =============