diff --git a/lib/backend.py b/lib/backend.py
index 7d02da8629c1aeb8f03c32f88a41169586c9d833..65e8cced8f1cfb4ec04b8778514e6cc4afb69bbf 100644
--- a/lib/backend.py
+++ b/lib/backend.py
@@ -261,7 +261,7 @@ def NodeVolumes():
       'vg': line[3].strip(),
     }
 
-  return [map_line(line.split('|')) for line in result.output.splitlines()]
+  return [map_line(line.split('|')) for line in result.stdout.splitlines()]
 
 
 def BridgesExist(bridges_list):