--- statesaver.c	2006-02-04 18:56:12.000000000 +0000
+++ statesaver.c.orig	2007-07-23 04:31:01.000000000 +0000
@@ -44,7 +44,7 @@
     Py_INCREF(g);  /* exhausted -- can return 'g' itself */
     return g;
   }
-  if (f->f_nfreevars || f->f_ncells) {
+  if (PySequence_Length(co->co_freevars) || PySequence_Length(co->co_cellvars)) {
     PyErr_SetString(PyExc_ValueError, "generator has cell or free vars");
     return NULL;
   }
@@ -67,6 +67,8 @@
   PyFrameObject* f;
   PyFrameObject* f2;
   PyCodeObject* co;
+  PyCodeObject* code;
+  PyCodeObject* code2;
   int i, res;
 
   if (g != g2)
@@ -94,8 +96,8 @@
         PyErr_SetString(PyExc_TypeError, "returned gi_frame");
         return -1;
       }
-      f2 = (PyFrameObject*) x;
-      if (f2->f_stacksize != f->f_stacksize) {
+      code2 = (PyFrameObject*) x;
+      if (code2->co_stacksize != code->co_stacksize) {
         PyErr_SetString(PyExc_TypeError, "stack size mismatch");
         return -1;
       }