diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6c4afbe4..90cd7c47 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+# 1.21.0 (25 December 2025)
+- [#1408](https://github.com/wiremock/WireMock.Net/pull/1408) - Fix readyness-check for Testcontainers [bug] contributed by [StefH](https://github.com/StefH)
+
 # 1.20.0 (24 December 2025)
 - [#1399](https://github.com/wiremock/WireMock.Net/pull/1399) - Upgrade RamlToOpenApiConverter and YamlDotNet [feature] contributed by [StefH](https://github.com/StefH)
 - [#1400](https://github.com/wiremock/WireMock.Net/pull/1400) - Add WireMock.Net.NUnit project [feature] contributed by [StefH](https://github.com/StefH)
diff --git a/Directory.Build.props b/Directory.Build.props
index e98fb3ce..2d759004 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -4,7 +4,7 @@
     </PropertyGroup>
 
     <PropertyGroup>
-        <VersionPrefix>1.20.0</VersionPrefix>
+        <VersionPrefix>1.21.0</VersionPrefix>
         <PackageIcon>WireMock.Net-Logo.png</PackageIcon>
         <PackageProjectUrl>https://github.com/wiremock/WireMock.Net</PackageProjectUrl>
         <PackageLicenseExpression>Apache-2.0</PackageLicenseExpression>
diff --git a/Generate-ReleaseNotes.cmd b/Generate-ReleaseNotes.cmd
index 5a5e664b..4f63342a 100644
--- a/Generate-ReleaseNotes.cmd
+++ b/Generate-ReleaseNotes.cmd
@@ -1,6 +1,6 @@
 rem https://github.com/StefH/GitHubReleaseNotes
 
-SET version=1.20.0
+SET version=1.21.0
 
 GitHubReleaseNotes --output CHANGELOG.md --skip-empty-releases --exclude-labels wontfix test question invalid doc duplicate example environment --version %version% --token %GH_TOKEN%
 
diff --git a/PackageReleaseNotes.txt b/PackageReleaseNotes.txt
index d0d374b0..455ba620 100644
--- a/PackageReleaseNotes.txt
+++ b/PackageReleaseNotes.txt
@@ -1,8 +1,4 @@
-# 1.20.0 (24 December 2025)
-- #1399 Upgrade RamlToOpenApiConverter and YamlDotNet [feature]
-- #1400 Add WireMock.Net.NUnit project [feature]
-- #1405 Fix Testcontainers AddProtoDefinition [bug]
-- #1398 Upgrade YamlDotNet dependency [feature]
-- #1404 An exception occurs when adding multiple proto definitions in the TestContainer. [bug]
+# 1.21.0 (25 December 2025)
+- #1408 Fix readyness-check for Testcontainers [bug]
 
 The full release notes can be found here: https://github.com/wiremock/WireMock.Net/blob/master/CHANGELOG.md
\ No newline at end of file