--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2010-01-10  Bruno Haible  <bruno@clisp.org>
 
+	Tests for module 'unistr/u8-strlen'.
+	* modules/unistr/u8-strlen-tests: New file.
+	* tests/unistr/test-u8-strlen.c: New file.
+
 	Tests for module 'unistr/u32-prev'.
 	* modules/unistr/u32-prev-tests: New file.
 	* tests/unistr/test-u32-prev.c: New file.

new file mode 100644
--- /dev/null
+++ b/modules/unistr/u8-strlen-tests
@@ -0,0 +1,12 @@
+Files:
+tests/unistr/test-u8-strlen.c
+tests/macros.h
+
+Depends-on:
+
+configure.ac:
+
+Makefile.am:
+TESTS += test-u8-strlen
+check_PROGRAMS += test-u8-strlen
+test_u8_strlen_SOURCES = unistr/test-u8-strlen.c

new file mode 100644
--- /dev/null
+++ b/tests/unistr/test-u8-strlen.c
@@ -0,0 +1,50 @@
+/* Test of u8_strlen() function.
+   Copyright (C) 2010 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 "unistr.h"
+
+#include "macros.h"
+
+int
+main ()
+{
+  /* Empty string.  */
+  {
+    static const uint8_t input[] = { 0 };
+    ASSERT (u8_strlen (input) == 0);
+  }
+
+  /* Simple string.  */
+  { /* "Grüß Gott. Здравствуйте! x=(-b±sqrt(b²-4ac))/(2a)  日本語,中文,한글" */
+    static const uint8_t input[] =
+      { 'G', 'r', 0xC3, 0xBC, 0xC3, 0x9F, ' ', 'G', 'o', 't', 't', '.', ' ',
+        0xD0, 0x97, 0xD0, 0xB4, 0xD1, 0x80, 0xD0, 0xB0, 0xD0, 0xB2, 0xD1, 0x81,
+        0xD1, 0x82, 0xD0, 0xB2, 0xD1, 0x83, 0xD0, 0xB9, 0xD1, 0x82, 0xD0, 0xB5,
+        '!', ' ', 'x', '=', '(', '-', 'b', 0xC2, 0xB1, 's', 'q', 'r', 't', '(',
+        'b', 0xC2, 0xB2, '-', '4', 'a', 'c', ')', ')', '/', '(', '2', 'a', ')',
+        ' ', ' ', 0xE6, 0x97, 0xA5, 0xE6, 0x9C, 0xAC, 0xE8, 0xAA, 0x9E, ',',
+        0xE4, 0xB8, 0xAD, 0xE6, 0x96, 0x87, ',',
+        0xED, 0x95, 0x9C, 0xEA, 0xB8, 0x80, '\0'
+      };
+    ASSERT (u8_strlen (input) == SIZEOF (input) - 1);
+  }
+
+  return 0;
+}