diff --git a/RELEASE.md b/RELEASE.md
new file mode 100644
index 0000000000..563c65b542
--- /dev/null
+++ b/RELEASE.md
@@ -0,0 +1,5 @@
+## 0.42.1 - 2023-09-18
+
+### Features
+
+- - Revise the ITF format: Use only `{ "#bigint": "num" }`, even for small integers`
diff --git a/VERSION b/VERSION
index ebe902dc1d..339fd080af 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.42.1-SNAPSHOT
+0.42.1