diff --git a/build.mill b/build.mill
index 1c8854a..252cc60 100644
--- a/build.mill
+++ b/build.mill
@@ -31,7 +31,7 @@ object agent extends ScalaJSModule with PublishModule {
   // Publishing configuration - read from PUBLISH_VERSION env var (set by CI)
   // Task.Input ensures env var is re-evaluated each run (not cached)
   override def publishVersion = Task.Input {
-    Task.env.get("PUBLISH_VERSION").getOrElse("0.4.1")
+    Task.env.get("PUBLISH_VERSION").getOrElse("0.4.2-SNAPSHOT")
   }
 
   // Skip scaladoc generation - Scala.js facades cause doc errors
diff --git a/package.json b/package.json
index acd841d..13cbb7c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "scalagent",
-  "version": "0.4.1",
+  "version": "0.4.2-SNAPSHOT",
   "private": true,
   "type": "module",
   "description": "Scalagent - Type-safe Scala.js wrapper for the Claude Agent SDK",