diff --git a/bower.json b/bower.json
index ab66d6c..2d3a933 100644
--- a/bower.json
+++ b/bower.json
@@ -1,6 +1,9 @@
 {
   "name": "c3",
-  "main": "c3.js",
+  "main": [
+    "c3.css",
+    "c3.js"
+  ],
   "version": "0.2.4",
   "homepage": "https://github.com/masayuki0812/c3",
   "authors": [