diff --git a/package.json b/package.json
index 7458f5b..fb1fc18 100644
--- a/package.json
+++ b/package.json
@@ -39,6 +39,7 @@
     "yargs": "4.4.x",
     "node.extend": "1.1.x",
     "merge-stream": "1.0.x",
-    "rtlcss": "2.0.x"
+    "rtlcss": "2.0.x",
+    "through2": "2.0.x"
   }
 }