diff --git a/CHANGELOG.md b/CHANGELOG.md
index 64da156..a1fc461 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,10 @@
-## [*Unreleased*](https://github.com/thoughtbot/yesod-auth-oauth2/compare/v0.3.1...master)
+## [*Unreleased*](https://github.com/thoughtbot/yesod-auth-oauth2/compare/v0.4.0.0...master)
 
+None
 
+## [v0.4.0.0](https://github.com/thoughtbot/yesod-auth-oauth2/compare/v0.3.1...v0.4.0.0)
+
+- COMPATIBILITY: Allow `aeson-1.3`
 - COMPATIBILITY: Dropped a lot of information from `credsExtra`:
 
   **TL;DR**: you'll no longer find things like `username` or `email` as keys in
diff --git a/package.yaml b/package.yaml
index 9997b50..a1738f4 100644
--- a/package.yaml
+++ b/package.yaml
@@ -1,6 +1,6 @@
 ---
 name: yesod-auth-oauth2
-version: '0.3.1'
+version: '0.4.0.0'  # N.B. PVP-compliant Semver: 0.MAJOR.MINOR.PATCH
 synopsis: OAuth 2.0 authentication plugins
 description: Library to authenticate with OAuth 2.0 for Yesod web applications.
 category: Web