diff --git a/package.json b/package.json
index 8e066602..c01ac28c 100644
--- a/package.json
+++ b/package.json
@@ -15,7 +15,7 @@
         "url": "https://github.com/mishoo/UglifyJS2.git"
     },
     "dependencies": {
-        "async"      : "~0.2.6",
+        "async"      : "~0.9.0",
         "source-map" : "0.1.34",
         "yargs": "~1.3.3",
         "uglify-to-browserify": "~1.0.0"