diff --git a/virtManager/addhardware.py b/virtManager/addhardware.py
index ecb5fc83b..b1f62519c 100644
--- a/virtManager/addhardware.py
+++ b/virtManager/addhardware.py
@@ -1471,20 +1471,22 @@ class vmmAddHardware(vmmGObjectUI):
             return disk
 
         try:
+            used = []
             disk.bus = bus
             if cache:
                 disk.driver_cache = cache
 
             # Generate target
             if not self.is_customize_dialog:
-                used = []
                 disks = (self.vm.get_disk_devices() +
                          self.vm.get_disk_devices(inactive=True))
                 for d in disks:
                     used.append(d.target)
 
             prefer_ctrl = self._set_disk_controller(disk, controller_model, disks)
-            disk.generate_target(used, prefer_ctrl)
+
+            if not self.is_customize_dialog:
+                disk.generate_target(used, prefer_ctrl)
 
         except Exception, e:
             return self.err.val_err(_("Storage parameter error."), e)