diff --git a/CHANGELOG.md b/CHANGELOG.md
index 96585863..4861d623 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,13 @@
 This project uses [Semantic Versioning 2.0.0](https://semver.org/).
 
 
+## 4.0.6
+
+### Changed
+
+- Updated definitions.
+
+
 ## 4.0.5
 
 ### Changed
diff --git a/lib/public_suffix/version.rb b/lib/public_suffix/version.rb
index 2d2003d9..c9f93f10 100644
--- a/lib/public_suffix/version.rb
+++ b/lib/public_suffix/version.rb
@@ -9,5 +9,5 @@
 
 module PublicSuffix
   # The current library version.
-  VERSION = "4.0.5"
+  VERSION = "4.0.6"
 end