diff --git a/Tools/autotest/sim_arducopter.sh b/Tools/autotest/sim_arducopter.sh
index 28cadd060f..f5b1f28232 100755
--- a/Tools/autotest/sim_arducopter.sh
+++ b/Tools/autotest/sim_arducopter.sh
@@ -1,24 +1,28 @@
 #!/bin/bash
 
+killall -q ArduCopter.elf
+pkill -f sim_multicopter.py
+
 set -e
 set -x
 
-if [ $# -eq 1 ]; then
-    frame="$1"
-    target="sitl-$frame"
-else
-    frame="+"
-    target="sitl"
-fi
+target=sitl
+frame="+"
 
-case $frame in
-    +,X,quad)
-	target="sitl"
-	;;
-    octa)
-	target="sitl-octa"
-	;;
-esac
+if [ $# -gt 0 ]; then
+    case $1 in
+	+|X|quad)
+	    target="sitl"
+	    frame="$1"
+	    shift
+	    ;;
+	octa)
+	    target="sitl-octa"
+	    frame="$1"
+	    shift
+	    ;;
+    esac
+fi
 
 echo "Building with target $target for frame $frame"
 
@@ -36,4 +40,4 @@ rm -f $tfile
 gnome-terminal -e "../Tools/autotest/pysim/sim_multicopter.py --frame=$frame --home=-35.362938,149.165085,584,270"
 sleep 2
 popd
-mavproxy.py --master tcp:127.0.0.1:5760 --sitl 127.0.0.1:5501 --out 127.0.0.1:14550 --out 127.0.0.1:14551 --quadcopter
+mavproxy.py --master tcp:127.0.0.1:5760 --sitl 127.0.0.1:5501 --out 127.0.0.1:14550 --out 127.0.0.1:14551 --quadcopter $*