diff --git a/yard/package-lock.json b/yard/package-lock.json
index 7283a6d..19c76be 100644
--- a/yard/package-lock.json
+++ b/yard/package-lock.json
@@ -1470,9 +1470,9 @@
       }
     },
     "acorn": {
-      "version": "6.3.0",
-      "resolved": "https://nexus.247tech.io/repository/npm-group/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
     },
     "acorn-walk": {