diff --git a/ui/scripts/cloud.core.zone.js b/ui/scripts/cloud.core.zone.js
index 1e12c34b669..4bde72e19e4 100644
--- a/ui/scripts/cloud.core.zone.js
+++ b/ui/scripts/cloud.core.zone.js
@@ -764,7 +764,7 @@ function doEditZone2($actionLink, $detailsTab, $midmenuItem1, $readonlyFields, $
 	isValid &= validateIp("Internal DNS 1", $detailsTab.find("#internaldns1_edit"), $detailsTab.find("#internaldns1_edit_errormsg"), false);	//required
 	isValid &= validateIp("Internal DNS 2", $detailsTab.find("#internaldns2_edit"), $detailsTab.find("#internaldns2_edit_errormsg"), true);	//optional						
 	if ($("#tab_content_details #vlan_container").css("display") != "none") {
-		isValid &= validateString("Start VLAN Range", $detailsTab.find("#startvlan_edit"), $detailsTab.find("#startvlan_edit_errormsg"), false); //required
+		isValid &= validateString("Start VLAN Range", $detailsTab.find("#startvlan_edit"), $detailsTab.find("#startvlan_edit_errormsg"), true); //optional (Bug 5730 requested to change VLAN to be optional when updating zone)
 		isValid &= validateString("End VLAN Range", $detailsTab.find("#endvlan_edit"), $detailsTab.find("#endvlan_edit_errormsg"), true);  //optional
 	}
 	isValid &= validateCIDR("Guest CIDR", $detailsTab.find("#guestcidraddress_edit"), $detailsTab.find("#guestcidraddress_edit_errormsg"), false);	//required