fix version number
diff --git a/package.json b/package.json
index cef3c17..dec614e 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "echarts",
-  "version": "4.2.0-rc1",
+  "version": "4.2.0-rc.1",
   "description": "A powerful charting and visualization library for browser",
   "keywords": [
     "visualization",