diff --git a/client/src/app.js b/client/src/app.js
index e7832aef79..14fcd5b65b 100644
--- a/client/src/app.js
+++ b/client/src/app.js
@@ -319,6 +319,18 @@ function (
          */
         broadcastChannel: null,
 
+        /**
+         * @private
+         * @type {module:date-time.Class|null}
+         */
+        dateTime: null,
+
+        /**
+         * @private
+         * @type {module:number.Class|null}
+         */
+        numberUtil: null,
+
         /**
          * @private
          */