diff --git a/CHANGELOG.md b/CHANGELOG.md
index 998f367..ed0046a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 4. New custom variable `chronometrist-task-list`, to add/hide tasks without modifying the database.
 5. New command `chronometrist-discard-active`, to discard the active interval.
 6. Debug logging messages - to view them, set `chronometrist-debug-enable`.
+7. `chronometrist-third`, an extension to add support for the [Third Time](https://www.lesswrong.com/posts/RWu8eZqbwgB9zaerh/third-time-a-better-way-to-work) system.
 
 ### Fixed
 1. Code to detect the type of change made to the file has been rewritten, hopefully fixing some uncommon `read` errors and `args out of range` errors.