diff --git a/package-lock.json b/package-lock.json
index 44d97da..0886751 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -57,10 +57,13 @@
       "dev": true
     },
     "async": {
-      "version": "0.9.2",
-      "resolved": "https://registry.npmjs.org/async/-/async-0.9.2.tgz",
-      "integrity": "sha1-rqdNXmHB+JlhO/ZL2mbUx48v0X0=",
-      "dev": true
+      "version": "2.6.4",
+      "resolved": "https://registry.npmjs.org/async/-/async-2.6.4.tgz",
+      "integrity": "sha512-mzo5dfJYwAn29PeiJ0zvwTo04zj8HDJj0Mn8TD7sno7q12prdbnasKJHhkm2c1LgrhlJ0teaea8860oxi51mGA==",
+      "dev": true,
+      "requires": {
+        "lodash": "^4.17.14"
+      }
     },
     "asynckit": {
       "version": "0.4.0",
@@ -677,6 +680,12 @@
         "type-check": "~0.3.2"
       }
     },
+    "lodash": {
+      "version": "4.17.21",
+      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
+      "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==",
+      "dev": true
+    },
     "log-driver": {
       "version": "1.2.5",
       "resolved": "https://registry.npmjs.org/log-driver/-/log-driver-1.2.5.tgz",
diff --git a/package.json b/package.json
index 0ea1d4f..bc3d60d 100644
--- a/package.json
+++ b/package.json
@@ -39,7 +39,7 @@
     "coverage": "node_modules/.bin/istanbul cover node_modules/.bin/_mocha -- --recursive"
   },
   "devDependencies": {
-    "async": "^0.9.0",
+    "async": "^2.6.4",
     "chai": "^1.10.0",
     "coveralls": "^2.11.2",
     "istanbul": "^0.4.5",