diff --git a/package.json b/package.json
index f990f12e..d6d80fed 100644
--- a/package.json
+++ b/package.json
@@ -25,7 +25,7 @@
     "url": "https://github.com/takuyaa/kuromoji.js/issues"
   },
   "dependencies": {
-    "async": "^0.9.0",
+    "async": "^1.4.0",
     "doublearray": "0.0.2",
     "zlibjs": "^0.2.0"
   },