diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 0ee8c01..2537c1f 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.3.0"
+  ".": "0.4.0"
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 07116c5..415776d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,31 @@
 # Changelog
 
+## [0.4.0](https://github.com/mshrtsr/fitting-rs/compare/0.3.0...0.4.0) (2022-08-19)
+
+
+### ⚠ BREAKING CHANGES
+
+* **gaussian:** Redesign API (#15)
+
+### Features
+
+* **gaussian:** Redesign API ([#15](https://github.com/mshrtsr/fitting-rs/issues/15)) ([14c9340](https://github.com/mshrtsr/fitting-rs/commit/14c9340b046c3e47086ae685705acb72faf25a50))
+
+
+### Bug Fixes
+
+* coverage using cargo-kcov ([d1ce724](https://github.com/mshrtsr/fitting-rs/commit/d1ce724c8482288ca4e98b0bf30b76531cec505a))
+
+
+### Chores
+
+* add CHANGELOG.md ([adefab3](https://github.com/mshrtsr/fitting-rs/commit/adefab34cd8171e54d37172ebeba8cccf93b13f7))
+* bootstrap releases for path: . ([#32](https://github.com/mshrtsr/fitting-rs/issues/32)) ([7096e8c](https://github.com/mshrtsr/fitting-rs/commit/7096e8c4aa13e7c66980df713b34cc9e8a4e5b43))
+* **deps:** update actions/cache action to v3 ([#28](https://github.com/mshrtsr/fitting-rs/issues/28)) ([aae4a4b](https://github.com/mshrtsr/fitting-rs/commit/aae4a4bf3c2e4bfa4c49a6acbeb4119e8f0c2b5b))
+* **deps:** update actions/checkout action to v3 ([#29](https://github.com/mshrtsr/fitting-rs/issues/29)) ([896bf16](https://github.com/mshrtsr/fitting-rs/commit/896bf16d27812a98b1e55a252ba6ae34c25c1921))
+* updated Cargo.toml (exclude section) ([fe52125](https://github.com/mshrtsr/fitting-rs/commit/fe52125da9fd3312a4053b9d2a47c864a238d56d))
+* updated README.md ([7422682](https://github.com/mshrtsr/fitting-rs/commit/7422682a6c08f57e191c037fdacf0554ec52de4f))
+
 ## [0.3.0](https://github.com/mshrtsr/fitting-rs/compare/0.2.1...0.3.0) (2020-05-16)
 
 - Migrate from the `failure` crate to `thiserror`.
diff --git a/Cargo.toml b/Cargo.toml
index 548808c..83949ae 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "fitting"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Masaharu TASHIRO <masatsr.kit@gmail.com>"]
 edition = "2018"
 # A short blurb about the package. This is not rendered in any format when