--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2011-09-20  Bruno Haible  <bruno@clisp.org>
+
+	Tests for module 'ioctl'.
+	* modules/ioctl-tests: New file.
+	* tests/test-ioctl.c: New file.
+
 2011-09-20  Bruno Haible  <bruno@clisp.org>
 
 	fcntl tests: EBADF tests.

new file mode 100644
--- /dev/null
+++ b/modules/ioctl-tests
@@ -0,0 +1,12 @@
+Files:
+tests/test-ioctl.c
+tests/signature.h
+tests/macros.h
+
+Depends-on:
+
+configure.ac:
+
+Makefile.am:
+TESTS += test-ioctl
+check_PROGRAMS += test-ioctl

new file mode 100644
--- /dev/null
+++ b/tests/test-ioctl.c
@@ -0,0 +1,49 @@
+/* Test of ioctl() function.
+   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/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <sys/ioctl.h>
+
+#include "signature.h"
+SIGNATURE_CHECK (ioctl, int, (int, int, ...));
+
+#include <errno.h>
+
+#include "macros.h"
+
+int
+main (void)
+{
+#ifdef FIONREAD
+  /* Test behaviour for invalid file descriptors.  */
+  {
+    int value;
+    errno = 0;
+    ASSERT (ioctl (-1, FIONREAD, &value) == -1);
+    ASSERT (errno == EBADF);
+  }
+  {
+    int value;
+    errno = 0;
+    ASSERT (ioctl (99, FIONREAD, &value) == -1);
+    ASSERT (errno == EBADF);
+  }
+#endif
+
+  return 0;
+}