diff --git a/string/test-strstr.c b/string/test-strstr.c
index 4115f7d2fd..86237555c0 100644
--- a/string/test-strstr.c
+++ b/string/test-strstr.c
@@ -17,21 +17,58 @@
    <https://www.gnu.org/licenses/>.  */
 
 #define TEST_MAIN
-#define TEST_NAME "strstr"
-#include "test-string.h"
+#ifndef WIDE
+# define TEST_NAME "strstr"
+# define TEST_FUNC strstr
+#else
+# define TEST_NAME "wcsstr"
+# define TEST_FUNC wcsstr
+#endif
+
+#ifndef WIDE
+# define CHAR char
+# define STRLEN strlen
+# define STRCPY strcpy
+# define MEMCPY memcpy
+# define MEMSET memset
+# define MEMPCPY mempcpy
+# define L(s) s
+#else
+# include <wchar.h>
+# define CHAR wchar_t
+# define STRLEN wcslen
+# define STRCPY wcscpy
+# define MEMCPY wmemcpy
+# define MEMSET wmemset
+# define MEMPCPY wmempcpy
+# define L(s) L ## s
+/* The test requires up to 8191 characters, so allocate at least 32Kb
+   (considering 4kb page size).  */
+# define BUF1PAGES 4
+#endif
 
+#include "test-string.h"
 
-#define STRSTR c_strstr
-#define libc_hidden_builtin_def(arg) /* nothing */
-#define __strnlen strnlen
-#include "strstr.c"
+#ifndef WIDE
+# define STRSTR c_strstr
+# define libc_hidden_builtin_def(arg) /* nothing */
+# define __strnlen strnlen
+# include "strstr.c"
+# define C_IMPL STRSTR
+#else
+# undef weak_alias
+# define weak_alias(a, b)
+# define WCSSTR c_wcsstr
+# include "wcsstr.c"
+# define C_IMPL WCSSTR
+#endif
 
 /* Naive implementation to verify results.  */
-static char *
-simple_strstr (const char *s1, const char *s2)
+static CHAR *
+simple_strstr (const CHAR *s1, const CHAR *s2)
 {
-  ssize_t s1len = strlen (s1);
-  ssize_t s2len = strlen (s2);
+  ssize_t s1len = STRLEN (s1);
+  ssize_t s2len = STRLEN (s2);
 
   if (s2len > s1len)
     return NULL;
@@ -43,29 +80,27 @@ simple_strstr (const char *s1, const char *s2)
 	if (s1[i + j] != s2[j])
 	  break;
       if (j == s2len)
-	return (char *) s1 + i;
+	return (CHAR *) s1 + i;
     }
 
   return NULL;
 }
 
 
-typedef char *(*proto_t) (const char *, const char *);
-
-IMPL (c_strstr, 0)
-IMPL (strstr, 1)
+typedef CHAR *(*proto_t) (const CHAR *, const CHAR *);
 
+IMPL (C_IMPL, 1)
+IMPL (TEST_FUNC, 1)
 
 static int
-check_result (impl_t *impl, const char *s1, const char *s2,
-	      char *exp_result)
+check_result (impl_t *impl, const CHAR *s1, const CHAR *s2,
+	      CHAR *exp_result)
 {
-  char *result = CALL (impl, s1, s2);
+  CHAR *result = CALL (impl, s1, s2);
   if (result != exp_result)
     {
-      error (0, 0, "Wrong result in function %s %s %s", impl->name,
-	     (result == NULL) ? "(null)" : result,
-	     (exp_result == NULL) ? "(null)" : exp_result);
+      error (0, 0, "Wrong result in function %s %p %p", impl->name,
+	     result, exp_result);
       ret = 1;
       return -1;
     }
@@ -74,7 +109,7 @@ check_result (impl_t *impl, const char *s1, const char *s2,
 }
 
 static void
-do_one_test (impl_t *impl, const char *s1, const char *s2, char *exp_result)
+do_one_test (impl_t *impl, const CHAR *s1, const CHAR *s2, CHAR *exp_result)
 {
   if (check_result (impl, s1, s2, exp_result) < 0)
     return;
@@ -85,49 +120,51 @@ static void
 do_test (size_t align1, size_t align2, size_t len1, size_t len2,
 	 int fail)
 {
-  char *s1 = (char *) (buf1 + align1);
-  char *s2 = (char *) (buf2 + align2);
+  align1 = align1 * sizeof (CHAR);
+  align2 = align2 * sizeof (CHAR);
 
-  static const char d[] = "1234567890abcdef";
-#define dl (sizeof (d) - 1)
-  char *ss2 = s2;
+  CHAR *s1 = (CHAR *) (buf1 + align1);
+  CHAR *s2 = (CHAR *) (buf2 + align2);
+
+  static const CHAR d[] = L("1234567890abcdef");
+  const size_t dl = STRLEN (d);
+  CHAR *ss2 = s2;
   for (size_t l = len2; l > 0; l = l > dl ? l - dl : 0)
     {
       size_t t = l > dl ? dl : l;
-      ss2 = mempcpy (ss2, d, t);
+      ss2 = MEMPCPY (ss2, d, t);
     }
   s2[len2] = '\0';
 
   if (fail)
     {
-      char *ss1 = s1;
+      CHAR *ss1 = s1;
       for (size_t l = len1; l > 0; l = l > dl ? l - dl : 0)
 	{
 	  size_t t = l > dl ? dl : l;
-	  memcpy (ss1, d, t);
+	  MEMCPY (ss1, d, t);
 	  ++ss1[len2 > 7 ? 7 : len2 - 1];
 	  ss1 += t;
 	}
     }
   else
     {
-      memset (s1, '0', len1);
-      memcpy (s1 + len1 - len2, s2, len2);
+      MEMSET (s1, '0', len1);
+      MEMCPY (s1 + len1 - len2, s2, len2);
     }
   s1[len1] = '\0';
 
   FOR_EACH_IMPL (impl, 0)
     do_one_test (impl, s1, s2, fail ? NULL : s1 + len1 - len2);
-
 }
 
 static void
 check1 (void)
 {
-  const char s1[] =
-    "F_BD_CE_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_C3_88_20_EF_BF_BD_EF_BF_BD_EF_BF_BD_C3_A7_20_EF_BF_BD";
-  const char s2[] = "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
-  char *exp_result;
+  const CHAR s1[] =
+    L("F_BD_CE_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_C3_88_20_EF_BF_BD_EF_BF_BD_EF_BF_BD_C3_A7_20_EF_BF_BD");
+  const CHAR s2[] = L("_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD");
+  CHAR *exp_result;
 
   exp_result = simple_strstr (s1, s2);
   FOR_EACH_IMPL (impl, 0)
@@ -137,30 +174,31 @@ check1 (void)
 static void
 check2 (void)
 {
-  const char s1_stack[] = ", enable_static, \0, enable_shared, ";
-  const size_t s1_byte_count = 18;
-  const char *s2_stack = &(s1_stack[s1_byte_count]);
-  const size_t s2_byte_count = 18;
-  char *exp_result;
+  const CHAR s1_stack[] = L(", enable_static, \0, enable_shared, ");
+  const size_t s1_char_count = 18;
+  const size_t s1_byte_len = 18 * sizeof (CHAR);
+  const CHAR *s2_stack = &(s1_stack[s1_char_count]);
+  const size_t s2_byte_len = 18 * sizeof (CHAR);
+  CHAR *exp_result;
   const size_t page_size_real = getpagesize ();
 
   /* Haystack at end of page.  The following page is protected.  */
-  char *s1_page_end = (void *) buf1 + page_size - s1_byte_count;
-  strcpy (s1_page_end, s1_stack);
+  CHAR *s1_page_end = (void *) buf1 + page_size - s1_byte_len;
+  STRCPY (s1_page_end, s1_stack);
 
   /* Haystack which crosses a page boundary.
      Note: page_size is at least 2 * getpagesize.  See test_init.  */
-  char *s1_page_cross = (void *) buf1 + page_size_real - 8;
-  strcpy (s1_page_cross, s1_stack);
+  CHAR *s1_page_cross = (void *) buf1 + page_size_real - 8;
+  STRCPY (s1_page_cross, s1_stack);
 
   /* Needle at end of page.  The following page is protected.  */
-  char *s2_page_end = (void *) buf2 + page_size - s2_byte_count;
-  strcpy (s2_page_end, s2_stack);
+  CHAR *s2_page_end = (void *) buf2 + page_size - s2_byte_len;
+  STRCPY (s2_page_end, s2_stack);
 
   /* Needle which crosses a page boundary.
      Note: page_size is at least 2 * getpagesize.  See test_init.  */
-  char *s2_page_cross = (void *) buf2 + page_size_real - 8;
-  strcpy (s2_page_cross, s2_stack);
+  CHAR *s2_page_cross = (void *) buf2 + page_size_real - 8;
+  STRCPY (s2_page_cross, s2_stack);
 
   exp_result = simple_strstr (s1_stack, s2_stack);
   FOR_EACH_IMPL (impl, 0)
@@ -184,8 +222,8 @@ check2 (void)
 static void
 pr23637 (void)
 {
-  char *h = (char*) buf1;
-  char *n = (char*) buf2;
+  CHAR *h = (CHAR*) buf1;
+  CHAR *n = (CHAR*) buf2;
 
   for (int i = 0; i < N; i++)
     {
@@ -200,7 +238,7 @@ pr23637 (void)
   /* Ensure we don't match at the first 'x'.  */
   h[0] = 'x';
 
-  char *exp_result = simple_strstr (h, n);
+  CHAR *exp_result = simple_strstr (h, n);
   FOR_EACH_IMPL (impl, 0)
     check_result (impl, h, n, exp_result);
 }
diff --git a/wcsmbs/Makefile b/wcsmbs/Makefile
index f3333c6a4b..1cddd8cc6d 100644
--- a/wcsmbs/Makefile
+++ b/wcsmbs/Makefile
@@ -163,6 +163,7 @@ tests := \
   test-wcspbrk \
   test-wcsrchr \
   test-wcsspn \
+  test-wcsstr \
   test-wmemchr \
   test-wmemcmp \
   test-wmemset \
diff --git a/wcsmbs/test-wcsstr.c b/wcsmbs/test-wcsstr.c
new file mode 100644
index 0000000000..23d6517255
--- /dev/null
+++ b/wcsmbs/test-wcsstr.c
@@ -0,0 +1,20 @@
+/* Test wcsstr function.
+   Copyright (C) 2024 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#define WIDE 1
+#include <string/test-strstr.c>
diff --git a/wcsmbs/wcsstr.c b/wcsmbs/wcsstr.c
index 78f1cc9ce0..b49630c1cf 100644
--- a/wcsmbs/wcsstr.c
+++ b/wcsmbs/wcsstr.c
@@ -28,8 +28,12 @@
 
 #include <wchar.h>
 
+#ifndef WCSSTR
+# define WCSSTR wcsstr
+#endif
+
 wchar_t *
-wcsstr (const wchar_t *haystack, const wchar_t *needle)
+WCSSTR (const wchar_t *haystack, const wchar_t *needle)
 {
   wchar_t b, c;
 
