diff --git a/VERSION b/VERSION
index b3d91f9c..054f94a2 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-5.9.0
+5.9.0-dev.1
diff --git a/package.json b/package.json
index a8bfe97e..bf96eb1a 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@kaitranntt/ccs",
-  "version": "5.9.0",
+  "version": "5.9.0-dev.1",
   "description": "Claude Code Switch - Instant profile switching between Claude Sonnet 4.5 and GLM 4.6",
   "keywords": [
     "cli",