diff --git a/examples/pytholite/uio.py b/examples/pytholite/uio.py
index 9a55856cf..0798210b5 100644
--- a/examples/pytholite/uio.py
+++ b/examples/pytholite/uio.py
@@ -1,5 +1,6 @@
 from migen.flow.network import *
 from migen.flow.transactions import *
+from migen.actorlib.sim import Dumper
 from migen.bus import wishbone
 from migen.bus.transactions import *
 from migen.uio.ioo import UnifiedIOSimulation