diff --git a/Include/ceval.h b/Include/ceval.h
index 7bd8179..a48d23c 100644
--- a/Include/ceval.h
+++ b/Include/ceval.h
@@ -112,10 +112,6 @@
 PyAPI_FUNC(PyObject *) PyEval_EvalFrame(struct _frame *);
 PyAPI_FUNC(PyObject *) PyEval_EvalFrameEx(struct _frame *f, int exc);
 
-/* this used to be handled on a per-thread basis - now just two globals */
-PyAPI_DATA(volatile int) _Py_Ticker;
-PyAPI_DATA(int) _Py_CheckInterval;
-
 /* Interface for threads.
 
    A module that plans to do a blocking system call (or something else
@@ -174,6 +170,9 @@
 PyAPI_FUNC(void) PyEval_ReleaseThread(PyThreadState *tstate);
 PyAPI_FUNC(void) PyEval_ReInitThreads(void);
 
+PyAPI_FUNC(void) _PyEval_SetSwitchInterval(unsigned long microseconds);
+PyAPI_FUNC(unsigned long) _PyEval_GetSwitchInterval(void);
+
 #define Py_BEGIN_ALLOW_THREADS { \
 			PyThreadState *_save; \
 			_save = PyEval_SaveThread();
@@ -192,6 +191,7 @@
 #endif /* !WITH_THREAD */
 
 PyAPI_FUNC(int) _PyEval_SliceIndex(PyObject *, Py_ssize_t *);
+PyAPI_FUNC(void) _PyEval_SignalAsyncExc(void);
 
 
 #ifdef __cplusplus
diff --git a/Include/pystate.h b/Include/pystate.h
index e02df88..c27e827 100644
--- a/Include/pystate.h
+++ b/Include/pystate.h
@@ -88,6 +88,8 @@
 
     PyObject *dict;  /* Stores per-thread state */
 
+    /* XXX doesn't mean anything anymore (the comment below is obsolete)
+       => deprecate or remove? */
     /* tick_counter is incremented whenever the check_interval ticker
      * reaches zero. The purpose is to give a useful measure of the number
      * of interpreted bytecode instructions in a given thread.  This
diff --git a/Include/sysmodule.h b/Include/sysmodule.h
index eeb8619..5078fe0 100644
--- a/Include/sysmodule.h
+++ b/Include/sysmodule.h
@@ -18,7 +18,6 @@
 			Py_GCC_ATTRIBUTE((format(printf, 1, 2)));
 
 PyAPI_DATA(PyObject *) _PySys_TraceFunc, *_PySys_ProfileFunc;
-PyAPI_DATA(int) _PySys_CheckInterval;
 
 PyAPI_FUNC(void) PySys_ResetWarnOptions(void);
 PyAPI_FUNC(void) PySys_AddWarnOption(const wchar_t *);