diff --git a/artiq/examples/kasli/repository/kasli_tester.py b/artiq/examples/kasli/repository/kasli_tester.py
index 8985aa345..4c4e14325 100644
--- a/artiq/examples/kasli/repository/kasli_tester.py
+++ b/artiq/examples/kasli/repository/kasli_tester.py
@@ -194,6 +194,8 @@ class KasliTester(EnvExperiment):
 
     @kernel
     def calibrate_urukul(self, channel):
+        self.core.break_realtime()
+        channel.init()
         self.core.break_realtime()
         sync_delay_seed, _ = channel.tune_sync_delay()
         self.core.break_realtime()