diff --git a/tests/core/twacube.test b/tests/core/twacube.test
index be3f4e213..d02897f24 100755
--- a/tests/core/twacube.test
+++ b/tests/core/twacube.test
@@ -1,7 +1,7 @@
 #!/bin/sh
 # -*- coding: utf-8 -*-
-# Copyright (C) 2014, 2015, 2016 Laboratoire de Recherche et Développement de
-# l'Epita (LRDE).
+# Copyright (C) 2014, 2015, 2016, 2018 Laboratoire de Recherche et
+# Développement de l'Epita (LRDE).
 #
 # This file is part of Spot, a model checking library.
 #
@@ -33,7 +33,7 @@ set -e
 run 0 ../twacube > stdout
 
 cat >expected <<EOF
-digraph G {
+digraph "" {
   rankdir=LR
   node [shape="circle"]
   I [label="", style=invis, width=0]
@@ -66,7 +66,7 @@ init : 0
 2 1  !p1 {}
 2 0  p1 {0,1}
 2 0  !p1&p2 {0,1}
-digraph G {
+digraph "" {
   rankdir=LR
   node [shape="circle"]
   I [label="", style=invis, width=0]