diff --git a/bundle/scripts/build.js b/bundle/scripts/build.js
index 05cf37ce..4266942f 100644
--- a/bundle/scripts/build.js
+++ b/bundle/scripts/build.js
@@ -89,7 +89,7 @@ function walk(dir) {
 	var results = [];
 	var list = fs.readdirSync(dir);
 	list.forEach(function (file) {
-		file = dir + "/" + file;
+		file = path.join(dir, file);
 		var stat = fs.statSync(file);
 		if (stat && stat.isDirectory()) {
 			/* Recurse into a subdirectory */