diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5710b712..27700b70 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 All notable changes to this project will be documented in this file.
 
 ## Unreleased - ???
+- Add mutexes (locks) and reader-writer locks to ev module for thread coordination.
 - Add `parse-all` as a generalization of the `parse` function.
 - Add `os/cpu-count` to get the number of available processors on a machine