diff --git a/package.json b/package.json
index fb39ed91..f2e9bb95 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,7 @@
   "author": "Alexander Blair",
   "license": "MIT",
   "dependencies": {
-    "async": "2.1.4",
+    "async": "3.2.2",
     "bignum": "^0.12.5",
     "bluebird": "3.4.7",
     "body-parser": "^1.16.0",