diff --git a/kvmagent/kvmagent/plugins/vm_plugin.py b/kvmagent/kvmagent/plugins/vm_plugin.py
index 06ff40c657..3af8f3a2d9 100644
--- a/kvmagent/kvmagent/plugins/vm_plugin.py
+++ b/kvmagent/kvmagent/plugins/vm_plugin.py
@@ -825,6 +825,7 @@ def to_xmlobject(self):
         e(disk, 'target', None, {'dev': 'sd%s' % self.dev_letter, 'bus': 'scsi'})
         e(disk, 'wwn', self.volume.wwn)
         e(disk, 'address', None, {'type': 'drive', 'controller': '0', 'unit': str(self.volume.deviceId)})
+        e(disk, 'driver', None, {'discard': 'unmap'})
         if self.volume.shareable:
             e(disk, 'shareable')
         return disk