diff --git a/frappy/io.py b/frappy/io.py
index 6a572493..a79cb97c 100644
--- a/frappy/io.py
+++ b/frappy/io.py
@@ -61,7 +61,6 @@ class HasIO(Module):
                 ioname = opts.get('io') or f'{name}_io'
                 io = self.ioClass(ioname, srv.log.getChild(ioname), opts, srv)  # pylint: disable=not-callable
                 io.callingModule = []
-                srv.modules[ioname] = io
                 srv.secnode.add_module(io, ioname)
                 self.ioDict[self.uri] = ioname
             self.io = ioname