diff --git a/htools/Ganeti/Errors.hs b/htools/Ganeti/Errors.hs
index 391e37986f3bc22a9ecf9ba9e1b5a5a847e77628..cd4c6294821e2a280ed4c3e3462166bb84c1a4dc 100644
--- a/htools/Ganeti/Errors.hs
+++ b/htools/Ganeti/Errors.hs
@@ -67,8 +67,8 @@ $(genException "GanetiException"
   , ("ProgrammerError", [excErrMsg])
   , ("BlockDeviceError", [excErrMsg])
   , ("ConfigurationError", [excErrMsg])
-  , ("ConfigVersionMismatch", [ ("expCode", [t| Int |])
-                              , ("actCode", [t| Int |])])
+  , ("ConfigVersionMismatch", [ ("expVer", [t| Int |])
+                              , ("actVer", [t| Int |])])
   , ("ReservationError", [excErrMsg])
   , ("RemoteError", [excErrMsg])
   , ("SignatureError", [excErrMsg])
diff --git a/lib/errors.py b/lib/errors.py
index 035df4972ea1e05b2ebb828945c43fe323ec421e..444c2d082a97b2f6fb7b32a3140463de34d12c9a 100644
--- a/lib/errors.py
+++ b/lib/errors.py
@@ -169,8 +169,7 @@ class ResultValidationError(GenericError):
 class OpPrereqError(GenericError):
   """Prerequisites for the OpCode are not fulfilled.
 
-  This exception will have either one or two arguments. For the
-  two-argument construction, the second argument should be one of the
+  This exception has two arguments: an error message, and one of the
   ECODE_* codes.
 
   """