diff --git a/libio/tst_swprintf.c b/libio/tst_swprintf.c
index e4bd7f022a..8a2ffe60ec 100644
--- a/libio/tst_swprintf.c
+++ b/libio/tst_swprintf.c
@@ -1,10 +1,11 @@
+#include <array_length.h>
 #include <stdio.h>
-#include <wchar.h>
+#include <support/check.h>
 #include <sys/types.h>
+#include <wchar.h>
 
 
 static wchar_t buf[100];
-#define nbuf (sizeof (buf) / sizeof (buf[0]))
 static const struct
 {
   size_t n;
@@ -12,81 +13,57 @@ static const struct
   ssize_t exp;
 } tests[] =
   {
-    { nbuf, "hello world", 11 },
+    { array_length (buf), "hello world", 11 },
     { 0, "hello world", -1 },
+    { 1, "hello world", -1 },
+    { 2, "hello world", -1 },
+    { 11, "hello world", -1 },
+    { 12, "hello world", 11 },
     { 0, "", -1 },
-    { nbuf, "", 0 }
+    { array_length (buf), "", 0 }
   };
 
-int
-main (int argc, char *argv[])
+static int
+do_test (void)
 {
   size_t n;
-  int result = 0;
 
-  puts ("test 1");
-  n = swprintf (buf, nbuf, L"Hello %s", "world");
-  if (n != 11)
-    {
-      printf ("incorrect return value: %zd instead of 11\n", n);
-      result = 1;
-    }
-  else if (wcscmp (buf, L"Hello world") != 0)
-    {
-      printf ("incorrect string: L\"%ls\" instead of L\"Hello world\"\n", buf);
-      result = 1;
-    }
+  TEST_COMPARE (swprintf (buf, array_length (buf), L"Hello %s", "world"), 11);
+  TEST_COMPARE_STRING_WIDE (buf, L"Hello world");
 
-  puts ("test 2");
-  n = swprintf (buf, nbuf, L"Is this >%g< 3.1?", 3.1);
-  if (n != 18)
-    {
-      printf ("incorrect return value: %zd instead of 18\n", n);
-      result = 1;
-    }
-  else if (wcscmp (buf, L"Is this >3.1< 3.1?") != 0)
-    {
-      printf ("incorrect string: L\"%ls\" instead of L\"Is this >3.1< 3.1?\"\n",
-	      buf);
-      result = 1;
-    }
+  TEST_COMPARE (swprintf (buf, array_length (buf), L"Is this >%g< 3.1?", 3.1),
+		18);
+  TEST_COMPARE_STRING_WIDE (buf, L"Is this >3.1< 3.1?");
 
-  for (n = 0; n < sizeof (tests) / sizeof (tests[0]); ++n)
+  for (n = 0; n < array_length (tests); ++n)
     {
       ssize_t res = swprintf (buf, tests[n].n, L"%s", tests[n].str);
 
       if (tests[n].exp < 0 && res >= 0)
 	{
+	  support_record_failure ();
 	  printf ("swprintf (buf, %Zu, L\"%%s\", \"%s\") expected to fail\n",
 		  tests[n].n, tests[n].str);
-	  result = 1;
 	}
       else if (tests[n].exp >= 0 && tests[n].exp != res)
 	{
-	  printf ("swprintf (buf, %Zu, L\"%%s\", \"%s\") expected to return %Zd, but got %Zd\n",
+	  support_record_failure ();
+	  printf ("\
+swprintf (buf, %Zu, L\"%%s\", \"%s\") expected to return %Zd, but got %Zd\n",
 		  tests[n].n, tests[n].str, tests[n].exp, res);
-	  result = 1;
 	}
       else
 	printf ("swprintf (buf, %Zu, L\"%%s\", \"%s\") OK\n",
 		tests[n].n, tests[n].str);
     }
 
-  if (swprintf (buf, nbuf, L"%.0s", "foo") != 0
-      || wcslen (buf) != 0)
-    {
-      printf ("swprintf (buf, %Zu, L\"%%.0s\", \"foo\") create some output\n",
-	      nbuf);
-      result = 1;
-    }
+  TEST_COMPARE (swprintf (buf, array_length (buf), L"%.0s", "foo"), 0);
+  TEST_COMPARE_STRING_WIDE (buf, L"");
 
-  if (swprintf (buf, nbuf, L"%.0ls", L"foo") != 0
-      || wcslen (buf) != 0)
-    {
-      printf ("swprintf (buf, %Zu, L\"%%.0ls\", L\"foo\") create some output\n",
-	      nbuf);
-      result = 1;
-    }
+  TEST_COMPARE (swprintf (buf, array_length (buf), L"%.0ls", L"foo"), 0);
+  TEST_COMPARE_STRING_WIDE (buf, L"");
 
-  return result;
+  return 0;
 }
+
+#include <support/test-driver.c>