diff --git a/package-lock.json b/package-lock.json
index 3ff4e03..2b9b1a0 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -174,9 +174,12 @@
       "dev": true
     },
     "async": {
-      "version": "0.9.2",
-      "resolved": "https://registry.npmjs.org/async/-/async-0.9.2.tgz",
-      "integrity": "sha1-rqdNXmHB+JlhO/ZL2mbUx48v0X0="
+      "version": "2.6.4",
+      "resolved": "https://registry.npmjs.org/async/-/async-2.6.4.tgz",
+      "integrity": "sha512-mzo5dfJYwAn29PeiJ0zvwTo04zj8HDJj0Mn8TD7sno7q12prdbnasKJHhkm2c1LgrhlJ0teaea8860oxi51mGA==",
+      "requires": {
+        "lodash": "^4.17.14"
+      }
     },
     "async-each": {
       "version": "1.0.3",
@@ -1753,6 +1756,11 @@
         "package-json": "^4.0.0"
       }
     },
+    "lodash": {
+      "version": "4.17.21",
+      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
+      "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg=="
+    },
     "lowercase-keys": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/lowercase-keys/-/lowercase-keys-1.0.1.tgz",
diff --git a/package.json b/package.json
index 96b1ea5..d65d636 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,7 @@
     "deploy": "git push heroku master"
   },
   "dependencies": {
-    "async": "^0.9.0",
+    "async": "^2.6.4",
     "basic-auth": "~1.0.0",
     "bcrypt": ">=5.0.0",
     "body-parser": "~1.10.1",