diff --git a/package.json b/package.json
index 13f63c6..b6ef86f 100644
--- a/package.json
+++ b/package.json
@@ -39,6 +39,7 @@
   },
   "dependencies": {
     "acorn": "^1.1.0",
+    "magic-string": "^0.5.1",
     "sander": "^0.3.3"
   },
   "files": [