diff --git a/package.json b/package.json
index 78197a7..676c8dc 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
   "version": "6.3.0",
   "description": "A plugin for adding CSRF protection to Fastify.",
   "main": "index.js",
+  "type": "commonjs",
   "types": "types/index.d.ts",
   "scripts": {
     "lint": "standard",