diff --git a/src/serve_raster.js b/src/serve_raster.js
index 4061dbb..8238143 100644
--- a/src/serve_raster.js
+++ b/src/serve_raster.js
@@ -36,7 +36,7 @@ module.exports = function(maps, options, prefix) {
       domains = options.domains,
       tilePath = '/{z}/{x}/{y}.{format}';
 
-  var rootPath = path.join(process.cwd(), options.root);
+  var rootPath = path.join(process.cwd(), options.root || '');
 
   var styleUrl = options.style;
   var map = {
diff --git a/src/serve_vector.js b/src/serve_vector.js
index 51e4278..2b43d30 100644
--- a/src/serve_vector.js
+++ b/src/serve_vector.js
@@ -14,7 +14,7 @@ module.exports = function(maps, options, prefix) {
       domains = options.domains,
       tilePath = '/{z}/{x}/{y}.pbf';
 
-  var rootPath = path.join(process.cwd(), options.root);
+  var rootPath = path.join(process.cwd(), options.root || '');
 
   var mbtilesPath = options.mbtiles;
   var map = {