--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2008-02-24  Bruno Haible  <bruno@clisp.org>
 
+	* modules/environ-tests: New file.
+	* tests/test-environ.c: New file.
+
 	New module 'environ'.
 	* modules/environ: New file.
 	* lib/unistd.in.h (environ): New declaration.

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

new file mode 100644
--- /dev/null
+++ b/tests/test-environ.c
@@ -0,0 +1,45 @@
+/* Test of environ variable.
+   Copyright (C) 2008 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>, 2008.  */
+
+#include <config.h>
+
+#include <unistd.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+int
+main ()
+{
+  /* The environment variables that are set even in the weirdest situations
+     are HOME and PATH.
+     POSIX says that HOME is initialized by the system, and that PATH may be
+     unset.  But in practice it's more frequent to see HOME unset and PATH
+     set.  So we test the presence of PATH.  */
+  char **remaining_variables = environ;
+  char *string;
+
+  for (; (string = *remaining_variables) != NULL; remaining_variables++)
+    {
+      if (strncmp (string, "PATH=", 5) == 0)
+	/* Found the PATH environment variable.  */
+	return 0;
+    }
+  /* Failed to find the PATH environment variable.  */
+  return 1;
+}