diff --git a/Psychtoolbox/PsychHardware/CedrusResponseBox.m b/Psychtoolbox/PsychHardware/CedrusResponseBox.m
index b6e4ee705..de8b55d5d 100644
--- a/Psychtoolbox/PsychHardware/CedrusResponseBox.m
+++ b/Psychtoolbox/PsychHardware/CedrusResponseBox.m
@@ -1737,7 +1737,7 @@ function ClearQueues(handle)
     oldverb = IOPort('Verbosity', 0);
 
     % Open link:
-    [dev.link, errmsg] = IOPort('OpenSerialPort', port, sprintf('BaudRate=%i Parity=None DataBits=8 StopBits=1 FlowControl=Hardware ReceiveTimeout=1 ReceiveLatency=0.0001 ', baudrate));
+    [dev.link, errmsg] = IOPort('OpenSerialPort', port, sprintf('BaudRate=%i Parity=None DataBits=8 StopBits=1 FlowControl=None ReceiveTimeout=1 ReceiveLatency=0.0001 ', baudrate));
 
     IOPort('Verbosity', oldverb);