diff -r 58266f5101cc Objects/unicodeobject.c
--- a/Objects/unicodeobject.c	Tue Jan 26 21:46:03 2016 -0800
+++ b/Objects/unicodeobject.c	Wed Jan 27 16:49:34 2016 +0100
@@ -911,6 +911,7 @@ resize_compact(PyObject *unicode, Py_ssi
     else if (_PyUnicode_HAS_WSTR_MEMORY(unicode)) {
         PyObject_DEL(_PyUnicode_WSTR(unicode));
         _PyUnicode_WSTR(unicode) = NULL;
+        _PyUnicode_WSTR_LENGTH(unicode) = 0;
     }
 #ifdef Py_DEBUG
     unicode_fill_invalid(unicode, old_length);
@@ -1298,8 +1299,8 @@ PyUnicode_New(Py_ssize_t size, Py_UCS4 m
             _PyUnicode_WSTR(unicode) = (wchar_t *)data;
         }
         else {
+            _PyUnicode_WSTR(unicode) = NULL;
             _PyUnicode_WSTR_LENGTH(unicode) = 0;
-            _PyUnicode_WSTR(unicode) = NULL;
         }
     }
 #ifdef Py_DEBUG
@@ -3998,6 +3999,7 @@ PyUnicode_AsUnicodeAndSize(PyObject *uni
                 /* sizeof(wchar_t) == 2 */
                 PyObject_FREE(_PyUnicode_WSTR(unicode));
                 _PyUnicode_WSTR(unicode) = NULL;
+                _PyUnicode_WSTR_LENGTH(unicode) = 0;
                 Py_FatalError("Impossible unicode object state, wstr "
                               "and str should share memory already.");
                 return NULL;
@@ -15043,9 +15045,9 @@ unicode_subtype_new(PyTypeObject *type, 
     _PyUnicode_STATE(self).ascii = _PyUnicode_STATE(unicode).ascii;
     _PyUnicode_STATE(self).ready = 1;
     _PyUnicode_WSTR(self) = NULL;
+    _PyUnicode_WSTR_LENGTH(self) = 0;
     _PyUnicode_UTF8_LENGTH(self) = 0;
     _PyUnicode_UTF8(self) = NULL;
-    _PyUnicode_WSTR_LENGTH(self) = 0;
     _PyUnicode_DATA_ANY(self) = NULL;
 
     share_utf8 = 0;