diff --git a/package.json b/package.json
index 224362e..8c33bf4 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,7 @@
     "index.js",
     "type-detect.js"
   ],
-  "main": "./index.js",
+  "main": "./type-detect.js",
   "repository": {
     "type": "git",
     "url": "git+ssh://git@github.com/chaijs/type-detect.git"
diff --git a/rollup.conf.js b/rollup.conf.js
index 637968d..fe448b8 100644
--- a/rollup.conf.js
+++ b/rollup.conf.js
@@ -14,7 +14,7 @@ export default {
   output: {
     file: env === 'test' ? 'type-detect.test.js' : 'type-detect.js',
     name: 'typeDetect',
-    format: 'iife',
+    format: 'umd',
   },
   plugins,
 };