diff --git a/package-lock.json b/package-lock.json
index 66b5a3a..f4c958c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -15,6 +15,7 @@
       "resolved": "https://registry.npmjs.org/align-text/-/align-text-0.1.4.tgz",
       "integrity": "sha1-DNkKVhCT810KmSVsIrcGlDP60Rc=",
       "dev": true,
+      "optional": true,
       "requires": {
         "kind-of": "3.2.2",
         "longest": "1.0.1",
@@ -67,13 +68,10 @@
       "dev": true
     },
     "async": {
-      "version": "2.4.1",
-      "resolved": "https://registry.npmjs.org/async/-/async-2.4.1.tgz",
-      "integrity": "sha1-YqVrJ5yYoR0JhwlqAcw+6463u9c=",
-      "dev": true,
-      "requires": {
-        "lodash": "4.17.4"
-      }
+      "version": "3.2.2",
+      "resolved": "https://registry.npmjs.org/async/-/async-3.2.2.tgz",
+      "integrity": "sha512-H0E+qZaDEfx/FY4t7iLRv1W2fFI6+pyCeTw1uN20AQPiwqwM6ojPxHxdLv4z8hi2DtnW9BOckSspLucW7pIE5g==",
+      "dev": true
     },
     "asynckit": {
       "version": "0.4.0",
@@ -591,7 +589,8 @@
       "version": "1.1.5",
       "resolved": "https://registry.npmjs.org/is-buffer/-/is-buffer-1.1.5.tgz",
       "integrity": "sha1-Hzsm72E7IUuIy8ojzGwB2Hlh7sw=",
-      "dev": true
+      "dev": true,
+      "optional": true
     },
     "is-my-json-valid": {
       "version": "2.16.0",
@@ -740,6 +739,7 @@
       "resolved": "https://registry.npmjs.org/kind-of/-/kind-of-3.2.2.tgz",
       "integrity": "sha1-MeohpzS6ubuw8yRm2JOupR5KPGQ=",
       "dev": true,
+      "optional": true,
       "requires": {
         "is-buffer": "1.1.5"
       }
@@ -767,12 +767,6 @@
         "type-check": "0.3.2"
       }
     },
-    "lodash": {
-      "version": "4.17.4",
-      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.4.tgz",
-      "integrity": "sha1-eCA6TRwyiuHYbcpkYONptX9AVa4=",
-      "dev": true
-    },
     "lodash._baseassign": {
       "version": "3.2.0",
       "resolved": "https://registry.npmjs.org/lodash._baseassign/-/lodash._baseassign-3.2.0.tgz",
@@ -857,7 +851,8 @@
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/longest/-/longest-1.0.1.tgz",
       "integrity": "sha1-MKCy2jj3N3DoKUoNIuZiXtd9AJc=",
-      "dev": true
+      "dev": true,
+      "optional": true
     },
     "mime-db": {
       "version": "1.27.0",
@@ -1082,7 +1077,8 @@
       "version": "1.6.1",
       "resolved": "https://registry.npmjs.org/repeat-string/-/repeat-string-1.6.1.tgz",
       "integrity": "sha1-jcrkcOHIirwtYA//Sndihtp15jc=",
-      "dev": true
+      "dev": true,
+      "optional": true
     },
     "request": {
       "version": "2.79.0",
diff --git a/package.json b/package.json
index 7a78113..9faedbd 100644
--- a/package.json
+++ b/package.json
@@ -41,7 +41,7 @@
     "coverage": "node_modules/.bin/istanbul cover node_modules/.bin/_mocha -- --recursive"
   },
   "devDependencies": {
-    "async": "^2.4.1",
+    "async": "^3.2.2",
     "chai": "^4.0.2",
     "coveralls": "^2.13.1",
     "istanbul": "^0.4.5",