diff --git a/package-lock.json b/package-lock.json
index 25bc629..969ba2b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "marked-gfm-heading-id",
-  "version": "3.2.0",
+  "version": "4.0.0",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "marked-gfm-heading-id",
-      "version": "3.2.0",
+      "version": "4.0.0",
       "license": "MIT",
       "dependencies": {
         "github-slugger": "^2.0.0"
diff --git a/package.json b/package.json
index 6dd0962..437ac08 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "marked-gfm-heading-id",
-  "version": "3.2.0",
+  "version": "4.0.0",
   "description": "marked GFM heading ids",
   "main": "./lib/index.cjs",
   "module": "./src/index.js",