diff --git a/src/lib/nerf-dart.js b/src/lib/nerf-dart.js
new file mode 100644
index 00000000..2ae8bc39
--- /dev/null
+++ b/src/lib/nerf-dart.js
@@ -0,0 +1,14 @@
+// borrowed from https://github.com/npm/npm/blob/master/lib/config/nerf-dart.js
+const url = require('url')
+
+/* istanbul ignore next */
+module.exports = function toNerfDart (uri) {
+  let parsed = url.parse(uri)
+  delete parsed.protocol
+  delete parsed.auth
+  delete parsed.query
+  delete parsed.search
+  delete parsed.hash
+
+  return url.resolve(url.format(parsed), '.')
+}