diff --git a/artiq/test/coredevice/test_performance.py b/artiq/test/coredevice/test_performance.py
index 25902b624..52433c744 100644
--- a/artiq/test/coredevice/test_performance.py
+++ b/artiq/test/coredevice/test_performance.py
@@ -1,5 +1,6 @@
 import os
 import unittest
+import time
 
 from artiq.experiment import *
 from artiq.test.hardware_testbench import ExperimentCase