diff --git a/package.json b/package.json
index 864e371..5f6eceb 100644
--- a/package.json
+++ b/package.json
@@ -43,6 +43,11 @@
     "test": "npx mocha tests",
     "build": "node scripts/prepublish.js"
   },
+  "devDependencies": {
+    "codecov": "^3.8.3",
+    "nyc": "^15.1.0",
+    "mocha": "^10.2.0"
+  },
   "jspm": {
     "map": {
       "./punycode.js": {