diff --git a/drivers/comedi/drivers/comedi_test.c b/drivers/comedi/drivers/comedi_test.c
index f5199474c0e9..7025ca61d6d1 100644
--- a/drivers/comedi/drivers/comedi_test.c
+++ b/drivers/comedi/drivers/comedi_test.c
@@ -273,6 +273,7 @@ static int waveform_ai_cmdtest(struct comedi_device *dev,
 	/* Step 2a : make sure trigger sources are unique */
 
 	err |= comedi_check_trigger_is_unique(cmd->convert_src);
+	err |= comedi_check_trigger_is_unique(cmd->scan_begin_src);
 	err |= comedi_check_trigger_is_unique(cmd->stop_src);
 
 	/* Step 2b : and mutually compatible */