diff --git a/package.json b/package.json
index 96cc49bd..9a327eec 100644
--- a/package.json
+++ b/package.json
@@ -12,7 +12,7 @@
     "dependencies": {
         "acorn": ">=0.11.0",
         "amd-loader": "~0.0.5",
-        "async": "^0.9.0",
+        "async": "~0.2.7",
         "base64id": "~0.1.0",
         "c9": "0.1.0",
         "connect": "~2.12.0",