diff --git a/glib/gunicollate.c b/glib/gunicollate.c
index dbce0de1d..af4179571 100644
--- a/glib/gunicollate.c
+++ b/glib/gunicollate.c
@@ -401,6 +401,8 @@ g_utf8_collate_key (const gchar *str,
 
   str_norm = _g_utf8_normalize_wc (str, len, G_NORMALIZE_ALL_COMPOSE);
 
+  g_return_val_if_fail (str_norm != NULL, NULL);
+
   xfrm_len = wcsxfrm (NULL, (wchar_t *)str_norm, 0);
   result_wc = g_new (wchar_t, xfrm_len + 1);
   wcsxfrm (result_wc, (wchar_t *)str_norm, xfrm_len + 1);
diff --git a/glib/tests/unicode-normalize.c b/glib/tests/unicode-normalize.c
index 191e5bb98..3f4d4c571 100644
--- a/glib/tests/unicode-normalize.c
+++ b/glib/tests/unicode-normalize.c
@@ -182,6 +182,19 @@ test_unicode_normalize_invalid (void)
     }
 }
 
+static void
+test_unicode_normalize_bad_length (void)
+{
+  const char *input = "fórmula, vol. 2 (deluxe edition)";
+  gsize len = 2;
+  char *output;
+
+  output = g_utf8_normalize (input, len, G_NORMALIZE_ALL_COMPOSE);
+  g_assert_null (output);
+
+  g_free (output);
+}
+
 int
 main (int argc, char **argv)
 {
@@ -190,6 +203,7 @@ main (int argc, char **argv)
   g_test_add_func ("/unicode/normalize", test_unicode_normalize);
   g_test_add_func ("/unicode/normalize-invalid",
                    test_unicode_normalize_invalid);
+  g_test_add_func ("/unicode/normalize/bad-length", test_unicode_normalize_bad_length);
 
   return g_test_run ();
 }