diff --git a/CHANGES b/CHANGES
index 6df4547eb3..a8d92f29b5 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,7 @@
+6240.	[bug]		Use dedicated per-worker thread jemalloc memory
+			arenas for send buffers allocation to reduce memory
+			consumption and avoid lock contention. [GL #4038]
+
 6239.	[func]		Deprecate the 'dnssec-must-be-secure' option.
 			[GL #3700]
 
diff --git a/doc/notes/notes-current.rst b/doc/notes/notes-current.rst
index a57ad29ee5..d641a266f8 100644
--- a/doc/notes/notes-current.rst
+++ b/doc/notes/notes-current.rst
@@ -68,6 +68,11 @@ Bug Fixes
 - The value of :any:`stale-refresh-time` was set to zero after ``rndc flush``.
   This has been fixed. :gl:`#4278`
 
+- BIND could consume more memory than it needs. That has been fixed by
+  using specialised jemalloc memory arenas dedicated to sending buffers. It
+  allowed us to optimize the process of returning memory pages back to
+  the operating system. :gl:`#4038`
+
 Known Issues
 ~~~~~~~~~~~~