diff --git a/package.json b/package.json
index 988f49a..42203ae 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "month-days",
-	"version": "3.0.0",
+	"version": "4.0.0",
 	"description": "Get the number of days in a month",
 	"license": "MIT",
 	"repository": "sindresorhus/month-days",