diff --git a/package.json b/package.json
index 0d4e42d8..29d28c65 100644
--- a/package.json
+++ b/package.json
@@ -33,6 +33,8 @@
   "devDependencies": {
     "typescript": "^1.8.7",
     "less": "^2.6.0",
+    "rtlcss": "^2.1.2",
+    "autoprefixer": "^6.7.6",
     "semantic-ui-less": "^2.2.4"
   },
   "dependencies": {