diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4b439ff..06b19b0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,29 @@
 
 All notable changes to this project will be documented in this file.
 
+## 0.4.0 - 2026-09-07
+
+### Breaking Changes
+
+- feat!: N-team outcome prediction with draw mass, replacing the 2-team panic
+- refactor!: close the remaining API gaps from #21
+- fix!: apply competitor configuration whenever it is supplied
+
+### Bug Fixes
+
+- fix(release): skip the changelog hook during a dry run
+- fix: stop destroying tail precision in evidence and truncation
+- fix: reject convergence options that silently disable inference
+
+### Documentation
+
+- docs: correct drifted documentation and compile the README in CI
+
+### Features
+
+- feat: add expected information gain for active matchup selection
+- feat: let observers be shared, boxed, or borrowed
+
 ## 0.3.0 - 2026-09-01
 
 ### Breaking Changes
@@ -25,6 +48,7 @@ All notable changes to this project will be documented in this file.
 ### Miscellaneous Tasks
 
 - chore: ignore proptest regression seed files
+- chore: Release trueskill-tt version 0.3.0
 
 ### Performance
 
diff --git a/Cargo.toml b/Cargo.toml
index 9899734..19ac6f3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "trueskill-tt"
-version = "0.3.0"
+version = "0.4.0"
 edition = "2024"
 rust-version = "1.85"
 description = "TrueSkill Through Time: Bayesian skill rating that tracks how skill evolves over time, via Gaussian message passing"