diff --git a/src/netnode.py b/src/netnode.py
--- a/src/netnode.py
+++ b/src/netnode.py
@@ -12,6 +12,7 @@ lockFile=os.path.join(conf.directory,"di
 
 class FailedConnection(Exception): pass
 class LockedException(Exception): pass
+class IncompatibleException(Exception): pass
 
 
 class BaseConnection: # abstract