---- a/tests/BD_Shape/Makefile.am
-+++ b/tests/BD_Shape/Makefile.am
-@@ -21,8 +21,6 @@
- # For the most up-to-date information see the Parma Polyhedra Library
- # site: http://bugseng.com/products/ppl/ .
-
--AUTOMAKE_OPTIONS = serial-tests
--
- if VALGRIND_TESTS_ENABLED
-
- CHECKER = \
---- a/tests/Box/Makefile.am
-+++ b/tests/Box/Makefile.am
-@@ -21,8 +21,6 @@
- # For the most up-to-date information see the Parma Polyhedra Library
- # site: http://bugseng.com/products/ppl/ .
-
--AUTOMAKE_OPTIONS = serial-tests
--
- if VALGRIND_TESTS_ENABLED
-
- CHECKER = \
---- a/tests/Concrete_Expression/Makefile.am
-+++ b/tests/Concrete_Expression/Makefile.am
-@@ -21,8 +21,6 @@
- # For the most up-to-date information see the Parma Polyhedra Library
- # site: http://bugseng.com/products/ppl/ .
-
--AUTOMAKE_OPTIONS = serial-tests
--
- if VALGRIND_TESTS_ENABLED
-
- CHECKER = \
---- a/tests/Octagonal_Shape/Makefile.am
-+++ b/tests/Octagonal_Shape/Makefile.am
-@@ -21,8 +21,6 @@
- # For the most up-to-date information see the Parma Polyhedra Library
- # site: http://bugseng.com/products/ppl/ .
-
--AUTOMAKE_OPTIONS = serial-tests
--
- if VALGRIND_TESTS_ENABLED
-
- CHECKER = \