diff --git a/package-lock.json b/package-lock.json
index 89066d6..b56480a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -449,12 +449,20 @@
       "dev": true
     },
     "async": {
-      "version": "2.6.0",
-      "resolved": "https://registry.npmjs.org/async/-/async-2.6.0.tgz",
-      "integrity": "sha512-xAfGg1/NTLBBKlHFmnd7PlmUW9KhVQIUuSrYem9xzFUZy13ScvtyGGejaae9iAVRiRq9+Cx7DPFaAAhCpyxyPw==",
+      "version": "2.6.4",
+      "resolved": "https://registry.npmjs.org/async/-/async-2.6.4.tgz",
+      "integrity": "sha512-mzo5dfJYwAn29PeiJ0zvwTo04zj8HDJj0Mn8TD7sno7q12prdbnasKJHhkm2c1LgrhlJ0teaea8860oxi51mGA==",
       "dev": true,
       "requires": {
-        "lodash": "^4.14.0"
+        "lodash": "^4.17.14"
+      },
+      "dependencies": {
+        "lodash": {
+          "version": "4.17.21",
+          "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
+          "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==",
+          "dev": true
+        }
       }
     },
     "async-each": {
diff --git a/package.json b/package.json
index 53aefaf..972fce4 100644
--- a/package.json
+++ b/package.json
@@ -49,7 +49,7 @@
     "ws": "4.1.0"
   },
   "devDependencies": {
-    "async": "2.6.0",
+    "async": "2.6.4",
     "chai": "4.2.0",
     "dirty-chai": "2.0.1",
     "eslint": "5.16.0",
diff --git a/yarn.lock b/yarn.lock
index 08d159a..5508efc 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -704,11 +704,11 @@ async@1.x, async@^1.4.0:
   version "1.5.2"
   resolved "https://registry.yarnpkg.com/async/-/async-1.5.2.tgz#ec6a61ae56480c0c3cb241c95618e20892f9672a"
 
-async@2.6.0:
-  version "2.6.0"
-  resolved "https://registry.yarnpkg.com/async/-/async-2.6.0.tgz#61a29abb6fcc026fea77e56d1c6ec53a795951f4"
+async@2.6.4:
+  version "2.6.4"
+  resolved "https://registry.yarnpkg.com/async/-/async-2.6.4.tgz#706b7ff6084664cd7eae713f6f965433b5504221"
   dependencies:
-    lodash "^4.14.0"
+    lodash "^4.17.14"
 
 asynckit@^0.4.0:
   version "0.4.0"
@@ -5134,11 +5134,7 @@ lodash@4.17.5:
   version "4.17.5"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.5.tgz#99a92d65c0272debe8c96b6057bc8fbfa3bed511"
 
-"lodash@4.6.1 || ^4.16.1", lodash@^4.0.0, lodash@^4.14.0, lodash@^4.2.0, lodash@^4.3.0, lodash@^4.5.1, lodash@^4.7.0:
-  version "4.17.4"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.4.tgz#78203a4d1c328ae1d86dca6460e369b57f4055ae"
-
-lodash@^4, lodash@^4.17.10, lodash@^4.17.11, lodash@^4.17.12, lodash@^4.17.13, lodash@^4.17.14, lodash@^4.17.15, lodash@^4.17.4, lodash@^4.17.5:
+"lodash@4.6.1 || ^4.16.1", lodash@^4, lodash@^4.0.0, lodash@^4.17.10, lodash@^4.17.11, lodash@^4.17.12, lodash@^4.17.13, lodash@^4.17.14, lodash@^4.17.15, lodash@^4.17.4, lodash@^4.17.5, lodash@^4.2.0, lodash@^4.3.0, lodash@^4.5.1, lodash@^4.7.0:
   version "4.17.15"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.15.tgz#b447f6670a0455bbfeedd11392eff330ea097548"