diff --git a/package.json b/package.json
index 3247eb1..f0ef06b 100644
--- a/package.json
+++ b/package.json
@@ -21,7 +21,7 @@
     "magicpen-prism": "^2.2.1"
   },
   "dependencies": {
-    "async": "1.4.0",
+    "async": "2.6.1",
     "escodegen": "1.7.0",
     "esprima": "4.0.1",
     "magicpen-prism": "^2.2.1",