diff --git a/artiq/devices/pdq2/mediator.py b/artiq/devices/pdq2/mediator.py
index f3c536219..64cb2703c 100644
--- a/artiq/devices/pdq2/mediator.py
+++ b/artiq/devices/pdq2/mediator.py
@@ -1,7 +1,6 @@
 from artiq.language.core import *
 from artiq.language.db import *
 from artiq.language.units import *
-from artiq.coredevice import ttl
 
 
 frame_setup = 20*ns