diff --git a/openstack_dashboard/static/js/horizon.instances.js b/openstack_dashboard/static/js/horizon.instances.js
index bc631e1a80..82ee94962b 100644
--- a/openstack_dashboard/static/js/horizon.instances.js
+++ b/openstack_dashboard/static/js/horizon.instances.js
@@ -88,7 +88,11 @@ horizon.addInitFunction(horizon.instances.init = function () {
    for selected image and flavor
    */
   function update_device_size(source_type) {
-    var volume_size = horizon.Quota.getSelectedFlavor().disk;
+    var volume_size;
+    var selected_flavor = horizon.Quota.getSelectedFlavor();
+    if (selected_flavor) {
+      volume_size = selected_flavor.disk;
+    }
     var size_field = $("#id_volume_size");
 
     if (source_type === 'image') {