diff --git a/CHANGES b/CHANGES
index 420cd05e7f..995638ee04 100644
--- a/CHANGES
+++ b/CHANGES
@@ -74,7 +74,9 @@
 			[GL !7206]
 
 5830.	[func]		Implement incremental resizing of isc_ht hash tables to
-			perform the rehashing gradually. [GL #3212]
+			perform the rehashing gradually. The catalog zone
+			implementation has been optimized to work with hundreds
+			of thousands of member zones. [GL #3212] [GL #3744]
 
 	--- 9.18.10 released ---
 
diff --git a/doc/notes/notes-current.rst b/doc/notes/notes-current.rst
index e58b5ec8d8..c5892c0d93 100644
--- a/doc/notes/notes-current.rst
+++ b/doc/notes/notes-current.rst
@@ -64,7 +64,8 @@ Removed Features
 Feature Changes
 ~~~~~~~~~~~~~~~
 
-- None.
+- The catalog zone implementation has been optimized to work with
+  hundreds of thousands of member zones. :gl:`#3212` :gl:`#3744`
 
 Bug Fixes
 ~~~~~~~~~