diff --git a/package-lock.json b/package-lock.json
index 1c525eb..3647a8e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -193,9 +193,9 @@
       "dev": true
     },
     "acorn": {
-      "version": "6.3.0",
-      "resolved": "https://registry.npmjs.org/acorn/-/acorn-6.3.0.tgz",
-      "integrity": "sha512-/czfa8BwS88b9gWQVhc8eknunSA2DoJpJyTQkhheIf5E48u1N0R4q/YxxsAeqRrmK9TQ/uYfgLDfZo91UlANIA==",
+      "version": "6.4.1",
+      "resolved": "https://registry.npmjs.org/acorn/-/acorn-6.4.1.tgz",
+      "integrity": "sha512-ZVA9k326Nwrj3Cj9jlh3wGFutC2ZornPNARZwsNYqQYgN0EsV2d53w5RN/co65Ohn4sUAUtb1rSUAOD6XN9idA==",
       "dev": true
     },
     "ajv": {
@@ -1977,7 +1977,8 @@
         "safe-buffer": {
           "version": "5.1.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -2083,7 +2084,8 @@
         "yallist": {
           "version": "3.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },