diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index 55b277ba0e6900cbc088d91ebb03d748167967f5..9075fd5f961f7a103d7b386b9c2c361828a90b74 100644
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -1523,8 +1523,11 @@ class LUSetClusterParams(LogicalUnit):
 
     """
     if self.op.vg_name is not None:
-      if self.op.vg_name != self.cfg.GetVGName():
-        self.cfg.SetVGName(self.op.vg_name)
+      new_volume = self.op.vg_name
+      if not new_volume:
+        new_volume = None
+      if new_volume != self.cfg.GetVGName():
+        self.cfg.SetVGName(new_volume)
       else:
         feedback_fn("Cluster LVM configuration already in desired"
                     " state, not changing")