diff --git a/package-lock.json b/package-lock.json
index 3e5cc20..a02ee7f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "cssstyle",
-  "version": "4.1.0",
+  "version": "4.2.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "cssstyle",
-      "version": "4.1.0",
+      "version": "4.2.0",
       "license": "MIT",
       "dependencies": {
         "@asamuzakjp/css-color": "^2.8.2",
diff --git a/package.json b/package.json
index b1517e3..d5d66ad 100644
--- a/package.json
+++ b/package.json
@@ -6,7 +6,7 @@
     "CSSStyleDeclaration",
     "StyleSheet"
   ],
-  "version": "4.1.0",
+  "version": "4.2.0",
   "homepage": "https://github.com/jsdom/cssstyle",
   "maintainers": [
     {