diff --git a/tools/python/xen/xend/server/DevController.py b/tools/python/xen/xend/server/DevController.py
index 1b94f14525..8141e890b1 100644
--- a/tools/python/xen/xend/server/DevController.py
+++ b/tools/python/xen/xend/server/DevController.py
@@ -82,7 +82,7 @@ class DevController:
         if backpath:
             xstransact.Remove(backpath)
         else:
-            raise VmError("Device not connected")
+            raise VmError("Device %s not connected" % devid)
            
 
     def configurations(self):