diff --git a/app/javascript/controllers/unsaved_changes_controller.js b/app/javascript/controllers/unsaved_changes_controller.js
index 781fb08..a8e1698 100644
--- a/app/javascript/controllers/unsaved_changes_controller.js
+++ b/app/javascript/controllers/unsaved_changes_controller.js
@@ -13,7 +13,8 @@ export default class extends Controller {
   } 
 
   formState() {
-    return JSON.stringify(new FormData(this.element).values().toArray().filter(x => x != ""))
+    return JSON.stringify(Array.from(new FormData(this.element).entries())
+                               .filter(x => x[1] != ""))
   }
   
   leavingPage(event) {