diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index 9159d9d179821e92ebbaa860d04f9c643e9be6d3..716f33ca27caa92dbd8925228858bff1c5d42053 100644
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -335,8 +335,8 @@ def _HasValidVG(vglist, vgname):
   if vgsize is None:
     return "volume group '%s' missing" % vgname
   elif vgsize < 20480:
-    return ("volume group '%s' too small (20480MiB required, %dMib found" %
-            vgname, vgsize)
+    return ("volume group '%s' too small (20480MiB required, %dMib found)" %
+            (vgname, vgsize))
   return None