diff --git a/package.json b/package.json
index fdf448c..a6eb1a4 100644
--- a/package.json
+++ b/package.json
@@ -16,6 +16,7 @@
     "test": "mocha",
     "cover": "nyc --reporter=html mocha"
   },
+  "main": "src/index.js",
   "author": "Tony Garnock-Jones <tonyg@leastfixedpoint.com>",
   "devDependencies": {
     "chai": "^4.2.0",