From 36738bdd1ba49ff83a7c72ad2a55fdef6bc40a11 Mon Sep 17 00:00:00 2001
From: Sophia Yang <sophia.yang@mongodb.com>
Date: Fri, 15 May 2026 15:37:24 -0400
Subject: [PATCH] changelog

---
 doc/changelog.rst | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/doc/changelog.rst b/doc/changelog.rst
index ed6f23f86..b3fd7e2f7 100644
--- a/doc/changelog.rst
+++ b/doc/changelog.rst
@@ -1,6 +1,13 @@
 Changelog
 =========
 
+Changes in Version 4.18.0 (2026/XX/XX)
+--------------------------------------
+PyMongo 4.18 brings a number of changes including:
+
+- Improved connection pool throughput under concurrent load by replacing the
+  single pool lock with fine-grained locks to reduce lock contention.
+
 Changes in Version 4.17.0 (2026/04/20)
 --------------------------------------