diff --git a/extdisplay.sh b/extdisplay.sh
index 7041e06..60c3ded 100755
--- a/extdisplay.sh
+++ b/extdisplay.sh
@@ -22,7 +22,7 @@ if [ -z $1 ]; then
 fi
 
 native=xrandr | grep LVDS | awk '{print $1}'
-plugged=xrandr | grep connected | grep -v $native | awk '{print $1}'
+plugged=xrandr | grep connected | grep -v ${native} | awk '{print $1}'
 
 if [ "$1" = solo ]; then
   xrandr --output ${plugged} --primary