diff --git a/package-lock.json b/package-lock.json
index 64027a9..df7167e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@seald-io/nedb",
-  "version": "3.1.0",
+  "version": "4.0.0-0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@seald-io/nedb",
-      "version": "3.1.0",
+      "version": "4.0.0-0",
       "license": "MIT",
       "dependencies": {
         "@seald-io/binary-search-tree": "^1.0.3",
diff --git a/package.json b/package.json
index c917644..5a57ddc 100755
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@seald-io/nedb",
-  "version": "3.1.0",
+  "version": "4.0.0-0",
   "files": [
     "lib/**/*.js",
     "browser-version/**/*.js",