diff -r 57550e1f57d9 Modules/atexitmodule.c
--- a/Modules/atexitmodule.c	Tue Mar 24 14:01:32 2015 +0100
+++ b/Modules/atexitmodule.c	Tue Mar 24 15:38:57 2015 +0100
@@ -97,7 +97,8 @@ atexit_callfuncs(void)
                 Py_XDECREF(exc_tb);
             }
             PyErr_Fetch(&exc_type, &exc_value, &exc_tb);
-            if (!PyErr_ExceptionMatches(PyExc_SystemExit)) {
+            if (exc_type
+                && !PyErr_GivenExceptionMatches(exc_type, PyExc_SystemExit)) {
                 PySys_WriteStderr("Error in atexit._run_exitfuncs:\n");
                 PyErr_NormalizeException(&exc_type, &exc_value, &exc_tb);
                 PyErr_Display(exc_type, exc_value, exc_tb);
diff -r 57550e1f57d9 Objects/genobject.c
--- a/Objects/genobject.c	Tue Mar 24 14:01:32 2015 +0100
+++ b/Objects/genobject.c	Tue Mar 24 15:38:57 2015 +0100
@@ -394,7 +394,8 @@ int
     PyObject *et, *ev, *tb;
     PyObject *value = NULL;
 
-    if (PyErr_ExceptionMatches(PyExc_StopIteration)) {
+    et = PyErr_Occurred();
+    if (et && PyErr_GivenExceptionMatches(et, PyExc_StopIteration)) {
         PyErr_Fetch(&et, &ev, &tb);
         Py_XDECREF(et);
         Py_XDECREF(tb);
@@ -403,7 +404,7 @@ int
             Py_INCREF(value);
             Py_DECREF(ev);
         }
-    } else if (PyErr_Occurred()) {
+    } else if (et) {
         return -1;
     }
     if (value == NULL) {
diff -r 57550e1f57d9 Python/ceval.c
--- a/Python/ceval.c	Tue Mar 24 14:01:32 2015 +0100
+++ b/Python/ceval.c	Tue Mar 24 15:38:57 2015 +0100
@@ -1940,9 +1940,13 @@ PyEval_EvalFrameEx(PyFrameObject *f, int
             Py_DECREF(v);
             if (retval == NULL) {
                 PyObject *val;
-                if (tstate->c_tracefunc != NULL
-                        && PyErr_ExceptionMatches(PyExc_StopIteration))
-                    call_exc_trace(tstate->c_tracefunc, tstate->c_traceobj, tstate, f);
+                if (tstate->c_tracefunc != NULL) {
+                    PyObject *exc_type = PyErr_Occurred();
+                    if (exc_type != NULL
+                        && PyErr_GivenExceptionMatches(exc_type, PyExc_StopIteration))
+                        call_exc_trace(tstate->c_tracefunc, tstate->c_traceobj,
+                                       tstate, f);
+                }
                 err = _PyGen_FetchStopIterationValue(&val);
                 if (err < 0)
                     goto error;
diff -r 57550e1f57d9 Python/errors.c
--- a/Python/errors.c	Tue Mar 24 14:01:32 2015 +0100
+++ b/Python/errors.c	Tue Mar 24 15:38:57 2015 +0100
@@ -210,7 +210,9 @@ PyErr_GivenExceptionMatches(PyObject *er
 int
 PyErr_ExceptionMatches(PyObject *exc)
 {
-    return PyErr_GivenExceptionMatches(PyErr_Occurred(), exc);
+    PyObject *cur_exc = PyErr_Occurred();
+    assert(cur_exc != NULL);
+    return PyErr_GivenExceptionMatches(cur_exc, exc);
 }