diff --git a/playground/package-lock.json b/playground/package-lock.json
index a59111c..40fbf5e 100644
--- a/playground/package-lock.json
+++ b/playground/package-lock.json
@@ -361,9 +361,9 @@
       }
     },
     "acorn": {
-      "version": "6.4.0",
-      "resolved": "https://registry.npmjs.org/acorn/-/acorn-6.4.0.tgz",
-      "integrity": "sha512-gac8OEcQ2Li1dxIEWGZzsp2BitJxwkwcOm0zHAJLcPJaVvm58FRnk6RkuLRpU1EujipU2ZFODv2P9DLMfnV8mw==",
+      "version": "6.4.1",
+      "resolved": "https://registry.npmjs.org/acorn/-/acorn-6.4.1.tgz",
+      "integrity": "sha512-ZVA9k326Nwrj3Cj9jlh3wGFutC2ZornPNARZwsNYqQYgN0EsV2d53w5RN/co65Ohn4sUAUtb1rSUAOD6XN9idA==",
       "dev": true
     },
     "ajv": {