diff --git a/test_zeros.sh b/test_zeros.sh
index 7d744657..1124463a 100755
--- a/test_zeros.sh
+++ b/test_zeros.sh
@@ -69,14 +69,17 @@ else
     sed "s/@FREEDV_RADIO_TO_COMPUTER_DEVICE@/$FREEDV_RADIO_TO_COMPUTER_DEVICE/g" $(pwd)/../$FREEDV_CONF_FILE.tmpl > $(pwd)/$FREEDV_CONF_FILE
 fi
 
-sed -i "s/@FREEDV_COMPUTER_TO_RADIO_DEVICE@/$FREEDV_COMPUTER_TO_RADIO_DEVICE/g" $(pwd)/$FREEDV_CONF_FILE
-sed -i "s/@FREEDV_COMPUTER_TO_SPEAKER_DEVICE@/$FREEDV_COMPUTER_TO_SPEAKER_DEVICE/g" $(pwd)/$FREEDV_CONF_FILE
+sed "s/@FREEDV_COMPUTER_TO_RADIO_DEVICE@/$FREEDV_COMPUTER_TO_RADIO_DEVICE/g" $(pwd)/$FREEDV_CONF_FILE > $(pwd)/$FREEDV_CONF_FILE.tmp
+mv $(pwd)/$FREEDV_CONF_FILE.tmp $(pwd)/$FREEDV_CONF_FILE
+sed "s/@FREEDV_COMPUTER_TO_SPEAKER_DEVICE@/$FREEDV_COMPUTER_TO_SPEAKER_DEVICE/g" $(pwd)/$FREEDV_CONF_FILE > $(pwd)/$FREEDV_CONF_FILE.tmp
+mv $(pwd)/$FREEDV_CONF_FILE.tmp $(pwd)/$FREEDV_CONF_FILE
 
 if [ "$FREEDV_MICROPHONE_TO_COMPUTER_DEVICE" == "FreeDV_Microphone_To_Computer" ] && [ "$OPERATING_SYSTEM" == "Linux" ]; then
-    sed -i "s/@FREEDV_MICROPHONE_TO_COMPUTER_DEVICE@/$FREEDV_MICROPHONE_TO_COMPUTER_DEVICE.monitor/g" $(pwd)/$FREEDV_CONF_FILE
+    sed "s/@FREEDV_MICROPHONE_TO_COMPUTER_DEVICE@/$FREEDV_MICROPHONE_TO_COMPUTER_DEVICE.monitor/g" $(pwd)/$FREEDV_CONF_FILE > $(pwd)/$FREEDV_CONF_FILE.tmp
 else
-    sed -i "s/@FREEDV_MICROPHONE_TO_COMPUTER_DEVICE@/$FREEDV_MICROPHONE_TO_COMPUTER_DEVICE/g" $(pwd)/$FREEDV_CONF_FILE
+    sed "s/@FREEDV_MICROPHONE_TO_COMPUTER_DEVICE@/$FREEDV_MICROPHONE_TO_COMPUTER_DEVICE/g" $(pwd)/$FREEDV_CONF_FILE > $(pwd)/$FREEDV_CONF_FILE.tmp
 fi
+mv $(pwd)/$FREEDV_CONF_FILE.tmp $(pwd)/$FREEDV_CONF_FILE
 
 # Start recording
 if [ "$FREEDV_TEST" == "tx" ]; then