diff --git a/package.json b/package.json
index 5f6ee77..10b4209 100644
--- a/package.json
+++ b/package.json
@@ -21,6 +21,7 @@
     "type": "git",
     "url": "https://github.com/pbeshai/d3-interpolate-path.git"
   },
+  "files": ["build/", "index.js"],
   "scripts": {
     "build": "rm -rf build && mkdir build && rollup --config rollup.config.js",
     "watch": "rollup --config rollup.config.js --watch",