diff --git a/dev/demo/vcdemo.js b/dev/demo/vcdemo.js
index d85f9fa..53ab75e 100644
--- a/dev/demo/vcdemo.js
+++ b/dev/demo/vcdemo.js
@@ -101,5 +101,10 @@
     KorAP.showQuery = function () {
       document.getElementById("query").innerHTML = vc.root().toQuery();
     };
+
+    // make the current vc persistant
+    KorAP.makeVCPersistant = function () {
+      vc.makePersistant();
+    };
   });
 });