--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2012-02-25  Bruno Haible  <bruno@clisp.org>
 
+	Tests for module 'log10l'.
+	* modules/log10l-tests: New file.
+	* tests/test-log10l.c: New file.
+	* tests/test-math-c++.cc: Check the declaration of log10l.
+
 	New module 'log10l'.
 	* lib/math.in.h (log10l): New declaration.
 	* lib/log10l.c: New file.

new file mode 100644
--- /dev/null
+++ b/modules/log10l-tests
@@ -0,0 +1,14 @@
+Files:
+tests/test-log10l.c
+tests/signature.h
+tests/macros.h
+
+Depends-on:
+fpucw
+
+configure.ac:
+
+Makefile.am:
+TESTS += test-log10l
+check_PROGRAMS += test-log10l
+test_log10l_LDADD = $(LDADD) @LOG10L_LIBM@

new file mode 100644
--- /dev/null
+++ b/tests/test-log10l.c
@@ -0,0 +1,45 @@
+/* Test of log10l() function.
+   Copyright (C) 2010-2012 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>, 2010.  */
+
+#include <config.h>
+
+#include <math.h>
+
+#include "signature.h"
+SIGNATURE_CHECK (log10l, long double, (long double));
+
+#include "fpucw.h"
+#include "macros.h"
+
+volatile long double x;
+long double y;
+
+int
+main ()
+{
+  DECL_LONG_DOUBLE_ROUNDING
+
+  BEGIN_LONG_DOUBLE_ROUNDING ();
+
+  /* A particular value.  */
+  x = 0.6L;
+  y = log10l (x);
+  ASSERT (y >= -0.2218487497L && y <= -0.2218487496L);
+
+  return 0;
+}

--- a/tests/test-math-c++.cc
+++ b/tests/test-math-c++.cc
@@ -172,6 +172,9 @@
 //SIGNATURE_CHECK (GNULIB_NAMESPACE::lgamma, double, (double));
 
 //SIGNATURE_CHECK (GNULIB_NAMESPACE::log10, double, (double));
+#if GNULIB_TEST_LOG10L
+SIGNATURE_CHECK (GNULIB_NAMESPACE::log10l, long double, (long double));
+#endif
 
 //SIGNATURE_CHECK (GNULIB_NAMESPACE::log1p, double, (double));