diff --git a/package.json b/package.json
index 2a1604e..292d948 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "japanese-date-converter",
-  "version": "0.2.7",
+  "version": "1.0.0",
   "description": "Convert western or japanese years into opposite years.",
   "module": "dist/japanese-date-converter.js",
   "main": "dist/japanese-date-converter.js",