--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2011-09-20  Bruno Haible  <bruno@clisp.org>
 
+	Tests for module 'sendto'.
+	* modules/sendto-tests: New file.
+	* tests/test-sendto.c: New file.
+
 	Tests for module 'send'.
 	* modules/send-tests: New file.
 	* tests/test-send.c: New file.

new file mode 100644
--- /dev/null
+++ b/modules/sendto-tests
@@ -0,0 +1,16 @@
+Files:
+tests/test-sendto.c
+tests/signature.h
+tests/macros.h
+
+Depends-on:
+netinet_in
+sockets
+inet_pton
+
+configure.ac:
+
+Makefile.am:
+TESTS += test-sendto
+check_PROGRAMS += test-sendto
+test_sendto_LDADD = $(LDADD) @LIBSOCKET@ $(INET_PTON_LIB)

new file mode 100644
--- /dev/null
+++ b/tests/test-sendto.c
@@ -0,0 +1,64 @@
+/* Test the sendto() 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>
+
+#include <sys/socket.h>
+
+#include "signature.h"
+SIGNATURE_CHECK (sendto, ssize_t,
+                 (int, const void *, size_t, int,
+                  const struct sockaddr *, socklen_t));
+
+#include <errno.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include "sockets.h"
+#include "macros.h"
+
+int
+main (void)
+{
+  gl_sockets_startup (SOCKETS_1_1);
+
+  /* Test behaviour for invalid file descriptors.  */
+  {
+    struct sockaddr_in addr;
+
+    addr.sin_family = AF_INET;
+    inet_pton (AF_INET, "127.0.0.1", &addr.sin_addr);
+    addr.sin_port = htons (80);
+    {
+      char byte = 'x';
+      errno = 0;
+      ASSERT (sendto (-1, &byte, 1, 0,
+                      (const struct sockaddr *) &addr, sizeof (addr))
+              == -1);
+      ASSERT (errno == EBADF);
+    }
+    {
+      char byte = 'x';
+      errno = 0;
+      ASSERT (sendto (99, &byte, 1, 0,
+                      (const struct sockaddr *) &addr, sizeof (addr))
+              == -1);
+      ASSERT (errno == EBADF);
+    }
+  }
+
+  return 0;
+}