diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index efaf1f5..087d02d 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "5.0.0-alpha.21.3"
+  ".": "5.0.0-alpha.21.4"
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 12893c2..3869a98 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## [5.0.0-alpha.21.4](https://github.com/fable-compiler/Fable.Python/compare/v5.0.0-alpha.21.3...v5.0.0-alpha.21.4) (2025-12-21)
+
+
+### Features
+
+* add Fable.Python.Testing module for cross-platform testing ([#186](https://github.com/fable-compiler/Fable.Python/issues/186)) ([2356705](https://github.com/fable-compiler/Fable.Python/commit/235670557cfb1913b9e67f7ad2e0fd4772a6de6b))
+
 ## [5.0.0-alpha.21.3](https://github.com/fable-compiler/Fable.Python/compare/v5.0.0-alpha.21.2...v5.0.0-alpha.21.3) (2025-12-19)