diff --git a/package.json b/package.json
index 447e76ca..20619661 100644
--- a/package.json
+++ b/package.json
@@ -40,6 +40,7 @@
     "dist/src",
     "src",
     "tests/testHelper.js",
+    "dist/testHelper.mjs",
     "sponsor-y.js"
   ],
   "dictionaries": {