diff --git a/CHANGELOG.md b/CHANGELOG.md
index db102e45..7e30064b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## [0.4.0] - 2018-07-30
 
 ### Removed
 
@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
  * Merged both examples into one
  * Rustfmt all the things :heavy_check_mark:
+ * Switched to [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 
 ## [0.3.2] - 2018-07-22
 
@@ -126,13 +127,13 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 * Better `Iterator` support for PyTuple, PyList, PyDict #75
 * Introduce IntoPyDictPointer similar to IntoPyTuple #69
 
-## [0.1.0] - 07-23-2017
+## 0.1.0 - 07-23-2017
 
 ### Added
 
 * Initial release
 
-[Unreleased]: https://github.com/olivierlacan/keep-a-changelog/compare/v0.3.2...HEAD
+[0.4.0]: https://github.com/olivierlacan/keep-a-changelog/compare/v0.3.2...v0.4.0
 [0.3.2]: https://github.com/pyo3/pyo3/compare/v0.3.1...v0.3.2
 [0.3.1]: https://github.com/pyo3/pyo3/compare/v0.3.0...v0.3.1
 [0.3.0]: https://github.com/pyo3/pyo3/compare/v0.2.7...v0.3.0
diff --git a/Cargo.toml b/Cargo.toml
index 6610dffc..6e52761b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pyo3"
-version = "0.3.2"
+version = "0.4.0"
 description = "Bindings to Python interpreter"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 readme = "README.md"
@@ -22,7 +22,7 @@ codecov = { repository = "PyO3/pyo3", branch = "master", service = "github" }
 libc = "0.2"
 spin = "0.4.6"
 num-traits = "0.2"
-pyo3cls = { path = "pyo3cls", version = "0.3.2" }
+pyo3cls = { path = "pyo3cls", version = "0.4.0" }
 mashup = "0.1.5"
 
 [dev-dependencies]
diff --git a/pyo3-derive-backend/Cargo.toml b/pyo3-derive-backend/Cargo.toml
index 73b61e88..c5bb7f40 100644
--- a/pyo3-derive-backend/Cargo.toml
+++ b/pyo3-derive-backend/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pyo3-derive-backend"
-version = "0.3.2"
+version = "0.4.0"
 description = "Code generation for PyO3 package"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 keywords = ["pyo3", "python", "cpython", "ffi"]
diff --git a/pyo3cls/Cargo.toml b/pyo3cls/Cargo.toml
index 9854b570..646d354a 100644
--- a/pyo3cls/Cargo.toml
+++ b/pyo3cls/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pyo3cls"
-version = "0.3.2"
+version = "0.4.0"
 description = "Proc macros for PyO3 package"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 keywords = ["pyo3", "python", "cpython", "ffi"]
@@ -22,7 +22,7 @@ features=["full", "parsing", "printing", "extra-traits"]
 
 [dependencies.pyo3-derive-backend]
 path = "../pyo3-derive-backend"
-version = "0.3.2"
+version = "0.4.0"
 
 [dependencies.proc-macro2]
 version = "0.4.9"