diff --git a/package.json b/package.json
index 99a5378..31cdcac 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "is-cidr",
-  "version": "3.1.1",
+  "version": "4.0.0",
   "description": "Check if a string is an IP address in CIDR notation",
   "author": "silverwind <me@silverwind.io>",
   "contributors": [