diff --git a/localedata/tst-setlocale.c b/localedata/tst-setlocale.c
new file mode 100644
index 0000000000..1f8e68d887
--- /dev/null
+++ b/localedata/tst-setlocale.c
@@ -0,0 +1,25 @@
+/* Test case by Jakub Jelinek <jakub@redhat.com>.  */
+#include <locale.h>
+#include <stdio.h>
+#include <string.h>
+
+int
+main (void)
+{
+  char q[30];
+  char *s;
+
+  setlocale (LC_ALL, "");
+  printf ("after setlocale (LC_ALL, \"\"): %s\n", setlocale(LC_NUMERIC, NULL));
+
+  strcpy (q, "de_DE.UTF-8");
+  setlocale (LC_NUMERIC, q);
+  printf ("after setlocale (LC_NUMERIC, \"%s\"): %s\n",
+	  q, setlocale(LC_NUMERIC, NULL));
+
+  strcpy (q, "de_DE.ISO-8859-1");
+  s = setlocale (LC_NUMERIC, NULL);
+  printf ("after overwriting string: %s\n", s);
+
+  return strcmp (s, "de_DE.UTF-8") != 0;
+}