diff --git a/lib/upgrade.txt b/lib/upgrade.txt
index 1718a6a7b65..6e58bee8b9e 100644
--- a/lib/upgrade.txt
+++ b/lib/upgrade.txt
@@ -1,6 +1,11 @@
 This files describes API changes in core libraries and APIs,
 information provided here is intended especially for developers.
 
+=== 4.3.8 ===
+
+* The `navigation_cache` class now uses the Moodle Universal Cache (MUC) to store the navigation cache data instead of storing
+  it in the global `$SESSION` variable.
+
 === 4.3.7 ===
 
 * The Moodle autoloader should now be registered using `\core\component::register_autoloader` rather