diff --git a/ChangeLog b/ChangeLog
index 96408874..014a2501 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2020-02-09  Mats Erik Andersson  <gnu@gisladisker.se>
+
+	test-snprintf: New test program.
+
+	An implementation dependent feature of snprintf() is tested.
+	The BSD unices and OpenSolaris relatives are known to be more
+	forgiving, than is Linux/glibc and kfreebsd/glibc.  The issue
+	was brought to our attention by Zhixiong Chi in:
+	https://lists.gnu.org/archive/html/bug-inetutils/2019-05/msg00002.html
+
+	* tests/test-snprintf.c: New file.
+	* tests/Makefile.am (check_PROGRAMS, TESTS): Add `test-snprintf'.
+	* tests/.gitignore: Likewise.
+
 2020-02-04  Mats Erik Andersson  <gnu@gisladisker.se>
 
 	Buffer overflow in tftp and tftpd.
diff --git a/tests/.gitignore b/tests/.gitignore
index fca21788..cb5d7988 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -5,6 +5,7 @@ ls
 readutmp
 runtime-ipv6
 tcpget
+test-snprintf
 tools.sh
 waitdaemon
 *.log
diff --git a/tests/Makefile.am b/tests/Makefile.am
index ab2d2dc9..34e68a11 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -23,7 +23,7 @@ LDADD = $(iu_LIBRARIES)
 noinst_PROGRAMS = identify
 identify_LDADD = $(top_builddir)/lib/libgnu.a $(LIBUTIL)
 
-check_PROGRAMS = localhost readutmp runtime-ipv6 waitdaemon
+check_PROGRAMS = localhost readutmp runtime-ipv6 test-snprintf waitdaemon
 
 dist_check_SCRIPTS = utmp.sh
 
@@ -86,7 +86,7 @@ if ENABLE_ifconfig
 dist_check_SCRIPTS += ifconfig.sh
 endif
 
-TESTS = localhost waitdaemon $(dist_check_SCRIPTS)
+TESTS = localhost test-snprintf waitdaemon $(dist_check_SCRIPTS)
 
 TESTS_ENVIRONMENT = EXEEXT=$(EXEEXT)
 
diff --git a/tests/test-snprintf.c b/tests/test-snprintf.c
new file mode 100644
index 00000000..317683f7
--- /dev/null
+++ b/tests/test-snprintf.c
@@ -0,0 +1,78 @@
+/* test-snprintf - Check whether snprintf allows doubly used strings.
+  Copyright (C) 2020 Free Software Foundation, Inc.
+
+  This file is part of GNU Inetutils.
+
+  GNU Inetutils 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.
+
+  GNU Inetutils 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 Mats Erik Andersson.  */
+
+/*
+ * It is not in violation of POSIX, but implementations of snprintf()
+ * differ in their ability to handle a situation where the target string
+ * to be produced by snprintf() is at the same time providing data, which
+ * are to be passed through the format string, and to be part of the new
+ * resulting string.  The different BSD unices, as well as OpenSolaris,
+ * are known to correctly handle this, whereas glibc is known to fail.
+ *
+ * This test issues a warning that non-portable behaviour is possible,
+ * should the program detect a discrepancy on this system.  If the
+ * program detects the macro PACKAGE to have value "inetutils", then
+ * get attention with the exit value 77, to fit with our testing
+ * frame work.
+ *
+ * When the environment variable VERBOSE is defined, an encouraging
+ * message is issued also in the presence of an enhanced implementation
+ * of snprintf().
+ */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define MESSAGE		"try a fool"
+#define WRONG_MESSAGE	"fool"
+
+int
+main (void)
+{
+  int err = 0;
+  char msg[sizeof (MESSAGE)] = "try a ";
+
+  snprintf (msg, sizeof (msg), "%s%s", msg, WRONG_MESSAGE);
+
+  if (!strcmp (msg, WRONG_MESSAGE))
+    {
+      printf ("Warning! This implementation of snprintf() is not able\n"
+	      "to handle string variables that appear as target and at the\n"
+	      "same time as source. This might be a portability issue!\n");
+#ifdef PACKAGE
+      if (!strcmp (PACKAGE, "inetutils"))
+	err = 77;
+#endif
+    }
+  else if (getenv ("VERBOSE"))
+    {
+      printf ("The present implementation of snprintf() allows the same\n"
+	      "string to act as target as well as source.  Good news!\n");
+    }
+
+  /* Always return successfully, as we are only producing a reminder,
+     rather than a show stopper.  */
+  return err;
+}