diff --git a/transmit.py b/transmit.py
index 28ed2909..f9b2fc2b 100644
--- a/transmit.py
+++ b/transmit.py
@@ -625,7 +625,7 @@ def transmit_carrier(duration):
 	global tx_doppler_freq_hz
 	global txLed
 	update_doppler("no")
-	command = "timeout " + str(duration) + " sudo tune -f " + str(tx_doppler_freq_hz) + " > /dev/null 2>&1" # 434.9e6
+	command = "timeout -k 0.5 " + str(duration) + " sudo tune -f " + str(tx_doppler_freq_hz) + " > /dev/null 2>&1" # 434.9e6
 	start = "sudo tune -f " + str(tx_doppler_freq_hz) + " &" # + " & > /dev/null 2>&1" # 434.9e6
 	stop = "sudo rpitx -f 434.9e6 &"
 	killrpitx = "sudo killall -9 rpitx &"