diff --git a/src/ltltest/lbt.test b/src/ltltest/lbt.test
index 27029f7cf..8d18408bf 100755
--- a/src/ltltest/lbt.test
+++ b/src/ltltest/lbt.test
@@ -19,6 +19,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 . ./defs
+set -e
 
 ltlfilt=../../bin/ltlfilt
 randltl=../../bin/randltl
diff --git a/src/ltltest/utf8.test b/src/ltltest/utf8.test
index 5e9c86a7e..61ac58ea8 100755
--- a/src/ltltest/utf8.test
+++ b/src/ltltest/utf8.test
@@ -1,5 +1,5 @@
 #! /bin/sh
-# Copyright (C) 2012 Laboratoire de Recherche et Developpement
+# Copyright (C) 2012, 2013 Laboratoire de Recherche et Developpement
 # de l'Epita (LRDE).
 #
 # This file is part of Spot, a model checking library.
@@ -21,6 +21,7 @@
 # Make sure
 
 . ./defs || exit 1
+set -e
 
 # ----
 run 0 ../ltl2text '□◯a' >out
diff --git a/src/tgbatest/dbacomp.test b/src/tgbatest/dbacomp.test
index c529a9ca5..7bce350bd 100755
--- a/src/tgbatest/dbacomp.test
+++ b/src/tgbatest/dbacomp.test
@@ -19,6 +19,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 . ./defs
+set -e
 
 # This automaton used to trigger a bug in the complementation: its
 # intersection with the complement was not empty!
diff --git a/src/tgbatest/ltlcross.test b/src/tgbatest/ltlcross.test
index bcd8bd513..38bcf0015 100755
--- a/src/tgbatest/ltlcross.test
+++ b/src/tgbatest/ltlcross.test
@@ -19,6 +19,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 . ./defs
+set -e
 
 ltl2tgba=../ltl2tgba
 
diff --git a/src/tgbatest/ltlcross2.test b/src/tgbatest/ltlcross2.test
index 367ed9e1f..b21e589d0 100755
--- a/src/tgbatest/ltlcross2.test
+++ b/src/tgbatest/ltlcross2.test
@@ -19,6 +19,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 . ./defs
+set -e
 
 ltl2tgba=../../bin/ltl2tgba
 
diff --git a/src/tgbatest/ltlcrossce.test b/src/tgbatest/ltlcrossce.test
index 81f1aa1a7..dbb532bd6 100755
--- a/src/tgbatest/ltlcrossce.test
+++ b/src/tgbatest/ltlcrossce.test
@@ -19,6 +19,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 . ./defs
+set -e
 
 ltl2tgba=../../bin/ltl2tgba