diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
index d90a4931..46b94894 100644
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,13 +1,24 @@
-# [3.1.0](https://github.com/RedPRL/yuujinchou/compare/3.0.0...3.1.0) (2022-07-11)
+# [4.0.0](https://github.com/RedPRL/yuujinchou/compare/3.1.0...4.0.0) (2022-12-16)
+
+### Features
 
+- register printers for yuujinchou effects ([#102](https://github.com/RedPRL/yuujinchou/issues/102)) ([3b89480](https://github.com/RedPRL/yuujinchou/commit/3b89480eaa250ba9a2b7de6b3086342d2cfb1a0d))
+- **Scope:** parametrize `Scope.Make` by a modifier ([#98](https://github.com/RedPRL/yuujinchou/issues/98)) ([4a2f3ef](https://github.com/RedPRL/yuujinchou/commit/4a2f3efb6ee565a18ac4ebef536e61214978b893))
+- **Trie:** add `Trie.untag` ([4671c83](https://github.com/RedPRL/yuujinchou/commit/4671c83b24c83a7df136ae62c80f2ecca9d76b22))
+- **Trie:** add type alias `untagged` ([031ac7a](https://github.com/RedPRL/yuujinchou/commit/031ac7aa1db3ac0ba1e0ba568fcc40fee3d2e2ae))
 
 ### BREAKING CHANGES
 
-* Use modules instead of records to pass effect handlers ([#94](https://github.com/RedPRL/yuujinchou/issues/94))
+- break the functor `Run` into `Run` and `TryWith` ([#97](https://github.com/RedPRL/yuujinchou/issues/97)) ([3ac136c](https://github.com/RedPRL/yuujinchou/commit/3ac136ccb283e9f0795e6a13e351a12a01a56f92))
+- use labelled arguments instead of functors ([#99](https://github.com/RedPRL/yuujinchou/issues/99)) ([256b5e7](https://github.com/RedPRL/yuujinchou/commit/256b5e726575d0912c28a1165ce49d9f6851dfda))
 
+# [3.1.0](https://github.com/RedPRL/yuujinchou/compare/3.0.0...3.1.0) (2022-07-11)
 
-# [3.0.0](https://github.com/RedPRL/yuujinchou/compare/2.0.0...3.0.0) (2022-06-03)
+### BREAKING CHANGES
 
+- Use modules instead of records to pass effect handlers ([#94](https://github.com/RedPRL/yuujinchou/issues/94))
+
+# [3.0.0](https://github.com/RedPRL/yuujinchou/compare/2.0.0...3.0.0) (2022-06-03)
 
 ### BREAKING CHANGES
 
@@ -21,27 +32,22 @@ Version 3.0.0 is a complete redesign and rewrite of the library, with the follow
 
 The old client code that works with yuujinchou 2.0.0 will stop working with the new version.
 
-
 # [2.0.0](https://github.com/RedPRL/yuujinchou/compare/1.0.0...2.0.0) (2022-03-07)
 
-
 ### Bug Fixes
 
-* **action:** pass rev_prefix to the final union ([#58](https://github.com/RedPRL/yuujinchou/issues/58)) ([000df38](https://github.com/RedPRL/yuujinchou/commit/000df384e4cb75773ed25b185f7c2a3f86acfdaa))
-
+- **action:** pass rev_prefix to the final union ([#58](https://github.com/RedPRL/yuujinchou/issues/58)) ([000df38](https://github.com/RedPRL/yuujinchou/commit/000df384e4cb75773ed25b185f7c2a3f86acfdaa))
 
 ### Code Refactoring
 
-* **trie:** drop almost all requirements of physical equality ([#54](https://github.com/RedPRL/yuujinchou/issues/54)) ([262e1be](https://github.com/RedPRL/yuujinchou/commit/262e1be09fed1005e5ddf87cc9f3d7de6810d79c))
-
+- **trie:** drop almost all requirements of physical equality ([#54](https://github.com/RedPRL/yuujinchou/issues/54)) ([262e1be](https://github.com/RedPRL/yuujinchou/commit/262e1be09fed1005e5ddf87cc9f3d7de6810d79c))
 
 ### Features
 
-* **action:** monadic union ([#57](https://github.com/RedPRL/yuujinchou/issues/57)) ([6a95ace](https://github.com/RedPRL/yuujinchou/commit/6a95aceed8469cd55a380edd70ebaa2fe5e143ca))
-* **trie:** monadic updates with Stdlib.result ([#55](https://github.com/RedPRL/yuujinchou/issues/55)) ([b2e783b](https://github.com/RedPRL/yuujinchou/commit/b2e783ba465865e0479a99ba9430e29b3956cc0d))
-
+- **action:** monadic union ([#57](https://github.com/RedPRL/yuujinchou/issues/57)) ([6a95ace](https://github.com/RedPRL/yuujinchou/commit/6a95aceed8469cd55a380edd70ebaa2fe5e143ca))
+- **trie:** monadic updates with Stdlib.result ([#55](https://github.com/RedPRL/yuujinchou/issues/55)) ([b2e783b](https://github.com/RedPRL/yuujinchou/commit/b2e783ba465865e0479a99ba9430e29b3956cc0d))
 
 ### BREAKING CHANGES
 
-* **action:** run and run\_with\_hooks now take a monadic merger
-* **trie:** drop all \*\_endo functions and physical equality requirements
+- **action:** run and run_with_hooks now take a monadic merger
+- **trie:** drop all \*\_endo functions and physical equality requirements