diff --git a/test/karma/test-sibling/package.json b/test/karma/test-sibling/package.json
index 6f539d972ff..fa6b19871d0 100644
--- a/test/karma/test-sibling/package.json
+++ b/test/karma/test-sibling/package.json
@@ -1,7 +1,7 @@
 {
   "name": "test-sibling",
-  "main": "dist/index.js",
-  "module": "dist/index.mjs",
+  "main": "dist/index.cjs.js",
+  "module": "dist/index.js",
   "collection": "dist/collection/collection-manifest.json",
   "types": "dist/types/components.d.ts"
-}
+}
\ No newline at end of file