diff --git a/qubesmanager/table_widgets.py b/qubesmanager/table_widgets.py
index 1a426de..c49d05f 100644
--- a/qubesmanager/table_widgets.py
+++ b/qubesmanager/table_widgets.py
@@ -509,7 +509,7 @@ class VmLastBackupItem(QtGui.QTableWidgetItem):
 
         if self.backup_timestamp:
             self.setText(
-                str(datetime.datetime.fromtimestamp(self.vm.backup_timestamp)))
+                str(datetime.datetime.fromtimestamp(self.backup_timestamp)))
         else:
             self.setText("")