diff --git a/basics/slides/themes/hugo-theme-pivotal-revealjs/static/plugin/multiplex/package.json b/basics/slides/themes/hugo-theme-pivotal-revealjs/static/plugin/multiplex/package.json
index bbed77a..4b17b0e 100644
--- a/basics/slides/themes/hugo-theme-pivotal-revealjs/static/plugin/multiplex/package.json
+++ b/basics/slides/themes/hugo-theme-pivotal-revealjs/static/plugin/multiplex/package.json
@@ -10,7 +10,7 @@
     "node": "~4.1.1"
   },
   "dependencies": {
-    "express": "~4.13.3",
+    "express": "~4.17.1",
     "grunt-cli": "~0.1.13",
     "mustache": "~2.2.1",
     "socket.io": "~1.3.7"