diff --git a/ui/scripts/ui-custom/autoscaler.js b/ui/scripts/ui-custom/autoscaler.js
index 6a36b885b63..0aa6c774d9d 100644
--- a/ui/scripts/ui-custom/autoscaler.js
+++ b/ui/scripts/ui-custom/autoscaler.js
@@ -357,6 +357,9 @@
                     click: function() {
                         var data = cloudStack.serializeForm($('.ui-dialog .autoscaler form'));
 
+                        // Fix for missing formData, when editing existing rules;
+                        if (!formData) formData = data;
+
                         // Pass VPC data
                         if (formData.tier) {
                             data.tier = formData.tier;