diff --git a/artiq/test/coredevice/test_analyzer.py b/artiq/test/coredevice/test_analyzer.py
index 335c941c3..cf8a64540 100644
--- a/artiq/test/coredevice/test_analyzer.py
+++ b/artiq/test/coredevice/test_analyzer.py
@@ -15,6 +15,8 @@ class CreateTTLPulse(EnvExperiment):
     def initialize_io(self):
         self.core.reset()
         self.loop_in.input()
+        self.loop_out.output()
+        delay(1*us)
         self.loop_out.off()
 
     @kernel