--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2011-09-11  Bruno Haible  <bruno@clisp.org>
 
+	Tests for module 'sys_types'.
+	* modules/sys_types-tests: New file.
+	* tests/test-sys_types.c: New file.
+
 	New module 'sys_types'.
 	* lib/sys_types.in.h: New file.
 	* m4/sys_types_h.m4: New file.

new file mode 100644
--- /dev/null
+++ b/modules/sys_types-tests
@@ -0,0 +1,11 @@
+Files:
+tests/test-sys_types.c
+
+Depends-on:
+sys_types-c++-tests
+
+configure.ac:
+
+Makefile.am:
+TESTS += test-sys_types
+check_PROGRAMS += test-sys_types

new file mode 100644
--- /dev/null
+++ b/tests/test-sys_types.c
@@ -0,0 +1,31 @@
+/* Test of <sys/types.h> substitute.
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This program 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 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2011.  */
+
+#include <config.h>
+
+#include <sys/types.h>
+
+/* Check that the types are all defined.  */
+pid_t t1;
+size_t t2;
+
+int
+main (void)
+{
+  return 0;
+}