diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
new file mode 100644
index 0000000..5e89f6e
--- /dev/null
+++ b/.github/workflows/release.yml
@@ -0,0 +1,27 @@
+name: Release and Changelog
+
+on:
+  push:
+    tags:
+      - "*"
+    branches:
+      - master
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v2
+
+    - name: Create Release
+      uses: actions/create-release@v1
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      with:
+        tag_name: ${{ github.ref }}
+        release_name: Release ${{ github.ref }}
+        body_path: CHANGELOG.txt
+        draft: false
+        prerelease: false
\ No newline at end of file
diff --git a/CHANGELOG.txt b/CHANGELOG.txt
new file mode 100644
index 0000000..365f64b
--- /dev/null
+++ b/CHANGELOG.txt
@@ -0,0 +1,17 @@
+## 0.4.0 - 2023-1-18
+
+### Added
+- Hazmat feature flag to expose Kyber primitives
+- NASM assembly code for better portability
+- CI runners for macOS and Windows
+- CI runners on tier 2 targets
+- Big endian testing
+- Error implementation
+
+### Changed
+- Bumped dependencies
+- Zeroise feature to Zeroize, no more British English in features 
+
+### Fixed
+- Documentation
+- Various CI issues
diff --git a/Cargo.toml b/Cargo.toml
index d60f8c7..b0e789d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pqc_kyber"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Mitchell Berry <foss@mitchellberry.com>"]
 edition = "2018"
 license = "MIT/Apache-2.0"
diff --git a/readme.md b/readme.md
index 414043d..502e4a3 100644
--- a/readme.md
+++ b/readme.md
@@ -16,7 +16,7 @@ A rust implementation of the Kyber algorithm, a KEM standardised by the NIST Pos
 This library:
 * Is no_std compatible and needs no allocator, suitable for embedded devices. 
 * Reference files contain no unsafe code and are written in pure rust.
-* On x86_64 platforms uses an avx2 optimized version by default, which includes some assembly code taken from the C repo. 
+* On x86_64 platforms offers an avx2 optimized version, which includes assembly from the C reference repo. 
 * Compiles to WASM using wasm-bindgen and has a ready-to-use binary published on NPM.