diff --git a/pjsip-apps/src/test-pjsua/scripts-pesq/100_defaults.py b/pjsip-apps/src/test-pjsua/scripts-pesq/100_defaults.py
index ffda20f..32454d7 100644
--- a/pjsip-apps/src/test-pjsua/scripts-pesq/100_defaults.py
+++ b/pjsip-apps/src/test-pjsua/scripts-pesq/100_defaults.py
@@ -12,6 +12,6 @@
 		"PESQ defaults pjsua settings",
 		[
 			InstanceParam("UA1", ADD_PARAM + " --max-calls=1 --play-file wavs/input.16.wav --auto-play-hangup"),
-			InstanceParam("UA2", ADD_PARAM + " --max-calls=1 --rec-file  wavs/tmp.16.wav --clock-rate 16000 --auto-answer 200 --auto-rec")
+			InstanceParam("UA2", "--null-audio --max-calls=1 --rec-file  wavs/tmp.16.wav --clock-rate 16000 --auto-answer 200 --auto-rec")
 		]
 		)