diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index de740effa..b44b28703 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "2.3.12"
+  ".": "2.4.0"
 }
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 53c21a800..a60c484e2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## [2.4.0](https://github.com/microsoft/OpenAPI.NET/compare/v2.3.12...v2.4.0) (2025-12-17)
+
+
+### Features
+
+* Add `type: "null"` downcasting when in oneOf and anyOf for OpenAPI v3 ([782cf8d](https://github.com/microsoft/OpenAPI.NET/commit/782cf8d1ff8166e3c7be706e08dabf168b9616a4))
+
 ## [2.3.12](https://github.com/microsoft/OpenAPI.NET/compare/v2.3.11...v2.3.12) (2025-12-15)
 
 
diff --git a/Directory.Build.props b/Directory.Build.props
index 26fffd5c2..caf63957a 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -12,7 +12,7 @@
     <PackageProjectUrl>https://github.com/Microsoft/OpenAPI.NET</PackageProjectUrl>
     <Copyright>© Microsoft Corporation. All rights reserved.</Copyright>
     <PackageTags>OpenAPI .NET</PackageTags>
-    <Version>2.3.12</Version>
+    <Version>2.4.0</Version>
   </PropertyGroup>
   <!-- https://github.com/clairernovotny/DeterministicBuilds#deterministic-builds -->
   <PropertyGroup Condition="'$(TF_BUILD)' == 'true'">