diff -r 8a47d2322df0 Include/frameobject.h
--- a/Include/frameobject.h	Tue Apr 10 21:05:53 2012 -0400
+++ b/Include/frameobject.h	Wed Apr 11 11:06:29 2012 +0100
@@ -37,7 +37,6 @@
            macros in ceval.c for details of their use. */
     PyObject *f_exc_type, *f_exc_value, *f_exc_traceback;
 
-    PyThreadState *f_tstate;
     int f_lasti;                /* Last instruction if called */
     /* Call PyFrame_GetLineNumber() instead of reading this field
        directly.  As of 2.3 f_lineno is only valid when tracing is
diff -r 8a47d2322df0 Lib/test/test_sys.py
--- a/Lib/test/test_sys.py	Tue Apr 10 21:05:53 2012 -0400
+++ b/Lib/test/test_sys.py	Wed Apr 11 11:06:29 2012 +0100
@@ -730,7 +730,7 @@
         nfrees = len(x.f_code.co_freevars)
         extras = x.f_code.co_stacksize + x.f_code.co_nlocals +\
                   ncells + nfrees - 1
-        check(x, size(vh + '12P3i' + CO_MAXBLOCKS*'3i' + 'P' + extras*'P'))
+        check(x, size(vh + '11P3i' + CO_MAXBLOCKS*'3i' + 'P' + extras*'P'))
         # function
         def func(): pass
         check(func, size(h + '12P'))
diff -r 8a47d2322df0 Objects/frameobject.c
--- a/Objects/frameobject.c	Tue Apr 10 21:05:53 2012 -0400
+++ b/Objects/frameobject.c	Wed Apr 11 11:06:29 2012 +0100
@@ -706,7 +706,6 @@
         Py_INCREF(locals);
         f->f_locals = locals;
     }
-    f->f_tstate = tstate;
 
     f->f_lasti = -1;
     f->f_lineno = code->co_firstlineno;
diff -r 8a47d2322df0 Python/ceval.c
--- a/Python/ceval.c	Tue Apr 10 21:05:53 2012 -0400
+++ b/Python/ceval.c	Wed Apr 11 11:06:29 2012 +0100
@@ -3741,7 +3741,7 @@
 call_trace(Py_tracefunc func, PyObject *obj, PyFrameObject *frame,
            int what, PyObject *arg)
 {
-    register PyThreadState *tstate = frame->f_tstate;
+    register PyThreadState *tstate = PyThreadState_GET();
     int result;
     if (tstate->tracing)
         return 0;
@@ -3757,8 +3757,8 @@
 PyObject *
 _PyEval_CallTracing(PyObject *func, PyObject *args)
 {
-    PyFrameObject *frame = PyEval_GetFrame();
-    PyThreadState *tstate = frame->f_tstate;
+    PyThreadState *tstate = PyThreadState_GET();
+    PyFrameObject *frame = tstate->frame;
     int save_tracing = tstate->tracing;
     int save_use_tracing = tstate->use_tracing;
     PyObject *result;
diff -r 8a47d2322df0 Python/sysmodule.c
--- a/Python/sysmodule.c	Tue Apr 10 21:05:53 2012 -0400
+++ b/Python/sysmodule.c	Wed Apr 11 11:06:29 2012 +0100
@@ -329,7 +329,7 @@
 
 
 static PyObject *
-call_trampoline(PyThreadState *tstate, PyObject* callback,
+call_trampoline(PyObject* callback,
                 PyFrameObject *frame, int what, PyObject *arg)
 {
     PyObject *args = PyTuple_New(3);
@@ -364,12 +364,11 @@
 profile_trampoline(PyObject *self, PyFrameObject *frame,
                    int what, PyObject *arg)
 {
-    PyThreadState *tstate = frame->f_tstate;
     PyObject *result;
 
     if (arg == NULL)
         arg = Py_None;
-    result = call_trampoline(tstate, self, frame, what, arg);
+    result = call_trampoline(self, frame, what, arg);
     if (result == NULL) {
         PyEval_SetProfile(NULL, NULL);
         return -1;
@@ -382,7 +381,6 @@
 trace_trampoline(PyObject *self, PyFrameObject *frame,
                  int what, PyObject *arg)
 {
-    PyThreadState *tstate = frame->f_tstate;
     PyObject *callback;
     PyObject *result;
 
@@ -392,7 +390,7 @@
         callback = frame->f_trace;
     if (callback == NULL)
         return 0;
-    result = call_trampoline(tstate, callback, frame, what, arg);
+    result = call_trampoline(callback, frame, what, arg);
     if (result == NULL) {
         PyEval_SetTrace(NULL, NULL);
         Py_XDECREF(frame->f_trace);