diff --git a/apps/recorder/interface.html b/apps/recorder/interface.html
index fdc1b07d7..069203360 100644
--- a/apps/recorder/interface.html
+++ b/apps/recorder/interface.html
@@ -7,6 +7,7 @@
 
     <script src="../../core/lib/interface.js"></script>
     <script src="../../core/js/ui.js"></script>
+    <script src="../../core/js/utils.js"></script>
     <script>
 var domTracks = document.getElementById("tracks");