diff --git a/CHANGELOG.md b/CHANGELOG.md
index 62e8cef..5b5bd2d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## v0.4.0
+
+- Added support for all [htmx response
+headers](https://htmx.org/reference/#response_headers) via a type implemention
+`IntoResponseParts`. These "responders" allow you to simply and safely apply the
+HX-* headers to any of your responses. Thanks to @pfz4 for the implementation
+work! (#5)
+
 ## v0.3.1
 
 - Rebuild docs with features enabled so `HxRequestGuardLayer` is visible on