diff --git a/artiq/test/coredevice/test_rtio.py b/artiq/test/coredevice/test_rtio.py
index 1a84b2f7d..92a0d1abc 100644
--- a/artiq/test/coredevice/test_rtio.py
+++ b/artiq/test/coredevice/test_rtio.py
@@ -613,7 +613,7 @@ class DMATest(ExperimentCase):
         exp.record_many(count)
         dt = self.dataset_mgr.get("dma_record_time")
         print("dt={}, dt/count={}".format(dt, dt/count))
-        self.assertLess(dt/count, 18*us)
+        self.assertLess(dt/count, 20*us)
 
     def test_dma_playback_time(self):
         exp = self.create(_DMA)