diff --git a/themes/hugo-theme-altinn/static/revealjs/plugin/multiplex/package.json b/themes/hugo-theme-altinn/static/revealjs/plugin/multiplex/package.json
index 1dcdfdc5f7..5dd14b078d 100644
--- a/themes/hugo-theme-altinn/static/revealjs/plugin/multiplex/package.json
+++ b/themes/hugo-theme-altinn/static/revealjs/plugin/multiplex/package.json
@@ -12,7 +12,7 @@
   "dependencies": {
     "express": "~4.19.0",
     "grunt-cli": "~0.1.13",
-    "mustache": "~2.2.1",
+    "mustache": "~4.2.0",
     "socket.io": "~1.3.7"
   },
   "license": "MIT"