diff --git a/src/tgbaalgos/isdet.cc b/src/tgbaalgos/isdet.cc
index be80419e6..d9ca3b0eb 100644
--- a/src/tgbaalgos/isdet.cc
+++ b/src/tgbaalgos/isdet.cc
@@ -106,6 +106,6 @@ namespace spot
   bool
   is_deterministic(const tgba* aut)
   {
-    return !!count_nondet_states_aux(aut, false);
+    return !count_nondet_states_aux(aut, false);
   }
 }
diff --git a/src/tgbatest/Makefile.am b/src/tgbatest/Makefile.am
index f9d95a427..3ddfa30f6 100644
--- a/src/tgbatest/Makefile.am
+++ b/src/tgbatest/Makefile.am
@@ -77,6 +77,7 @@ TESTS = \
   taatgba.test \
   tgbaread.test \
   renault.test \
+  nondet.test \
   neverclaimread.test \
   readsave.test \
   ltl2tgba.test \
diff --git a/src/tgbatest/nondet.test b/src/tgbatest/nondet.test
new file mode 100755
index 000000000..1cc7decd4
--- /dev/null
+++ b/src/tgbatest/nondet.test
@@ -0,0 +1,40 @@
+#!/bin/sh
+# -*- coding: utf-8 -*-
+# Copyright (C) 2012 Laboratoire de Recherche et Développement
+# de l'Epita (LRDE).
+#
+# This file is part of Spot, a model checking library.
+#
+# Spot is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# Spot is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+# or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+# License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Spot; see the file COPYING.  If not, write to the Free
+# Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+# 02111-1307, USA.
+
+. ./defs
+set -e
+
+../../bin/ltl2tgba FGa GFa --stats='%f %d' >out.1
+cat >expected.1<<EOF
+FGa 0
+GFa 1
+EOF
+
+cmp out.1 expected.1
+
+../../bin/ltl2tgba FGa GFa --stats='%f %d %n %s' >out.2
+cat >expected.2<<EOF
+FGa 0 1 2
+GFa 1 0 1
+EOF
+
+cmp out.2 expected.2