# Pastebin 1aGawBTa
diff -r 5b81f483c459 pypy/objspace/std/unicodeobject.py
--- a/pypy/objspace/std/unicodeobject.py        Fri Nov 24 15:14:15 2017 +0100
+++ b/pypy/objspace/std/unicodeobject.py        Fri Nov 24 15:20:51 2017 +0100
@@ -369,22 +369,16 @@
     @jit.elidable
     def title_unicode(self, value):
         input = self._utf8
-        builder = StringBuilder(len(input))
-        i = 0
+        builder = rutf8.Utf8StringBuilder(len(input))
         previous_is_cased = False
-        flag = self._get_flag()
-        while i < len(input):
-            ch = rutf8.codepoint_at_pos(input, i)
-            i = rutf8.next_codepoint_pos(input, i)
+        for ch in rutf8.Utf8StringIterator(input):
             if not previous_is_cased:
                 ch = unicodedb.totitle(ch)
             else:
                 ch = unicodedb.tolower(ch)
-            if ch >= 0x80:
-                flag = rutf8.combine_flags(flag, rutf8.FLAG_REGULAR)
-            rutf8.unichr_as_utf8_append(builder, ch, allow_surrogates=True)
+            builder.append_code(ch)
             previous_is_cased = unicodedb.iscased(ch)
-        return builder.build(), flag
+        return builder.build(), builder.get_flag()
 
     def descr_translate(self, space, w_table):
         input = self._utf8