diff --git a/start b/start
index ecf7eab..10ecdb9 100755
--- a/start
+++ b/start
@@ -35,7 +35,7 @@ cd "$(dirname "$0")"
 
 $SUDO true
 
-NET_CONF_FILE="$(sudo mktemp)"
+NET_CONF_FILE="$($SUDO mktemp)"
 
 # create bridge
 NET_CONF_FILE="$NET_CONF_FILE" $DEBUG $SUDO --preserve-env=NET_CONF_FILE \