Index: Objects/genobject.c
===================================================================
--- Objects/genobject.c	(revision 52849)
+++ Objects/genobject.c	(working copy)
@@ -77,6 +77,7 @@
 	Py_XINCREF(tstate->frame);
 	assert(f->f_back == NULL);
 	f->f_back = tstate->frame;
+        f->f_tstate = tstate;
 
 	gen->gi_running = 1;
 	result = PyEval_EvalFrameEx(f, exc);