diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index 4e7d47d..e4885d1 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -1687,6 +1687,96 @@
     Py_RETURN_NONE;
 }
 
+#ifdef WITH_THREAD
+typedef struct {
+    PyThread_type_lock start_event;
+    PyThread_type_lock exit_event;
+    PyObject *callback;
+} test_c_thread_t;
+
+static void
+temporary_c_thread(void *data)
+{
+    test_c_thread_t *test_c_thread = data;
+    PyGILState_STATE state;
+    PyObject *res;
+
+    PyThread_release_lock(test_c_thread->start_event);
+
+    /* Allocate a Python thread state for this thread */
+    state = PyGILState_Ensure();
+
+    res = PyObject_CallFunction(test_c_thread->callback, "", NULL);
+    Py_CLEAR(test_c_thread->callback);
+
+    if (res == NULL) {
+        PyErr_Print();
+    }
+    else {
+        Py_DECREF(res);
+    }
+
+    /* Destroy the Python thread state for this thread */
+    PyGILState_Release(state);
+
+    PyThread_release_lock(test_c_thread->exit_event);
+
+    PyThread_exit_thread();
+}
+
+static PyObject *
+call_in_temporary_c_thread(PyObject *self, PyObject *callback)
+{
+    PyObject *res = NULL;
+    test_c_thread_t test_c_thread;
+    long thread;
+
+    PyEval_InitThreads();
+
+    test_c_thread.start_event = PyThread_allocate_lock();
+    test_c_thread.exit_event = PyThread_allocate_lock();
+    test_c_thread.callback = NULL;
+    if (!test_c_thread.start_event || !test_c_thread.exit_event) {
+        PyErr_SetString(PyExc_RuntimeError, "could not allocate lock");
+        goto exit;
+    }
+
+    Py_INCREF(callback);
+    test_c_thread.callback = callback;
+
+    PyThread_acquire_lock(test_c_thread.start_event, 1);
+    PyThread_acquire_lock(test_c_thread.exit_event, 1);
+
+    thread = PyThread_start_new_thread(temporary_c_thread, &test_c_thread);
+    if (thread == -1) {
+        PyErr_SetString(PyExc_RuntimeError, "unable to start the thread");
+        PyThread_release_lock(test_c_thread.start_event);
+        PyThread_release_lock(test_c_thread.exit_event);
+        goto exit;
+    }
+
+    PyThread_acquire_lock(test_c_thread.start_event, 1);
+    PyThread_release_lock(test_c_thread.start_event);
+
+    Py_BEGIN_ALLOW_THREADS
+        PyThread_acquire_lock(test_c_thread.exit_event, 1);
+        PyThread_release_lock(test_c_thread.exit_event);
+    Py_END_ALLOW_THREADS
+
+    Py_INCREF(Py_None);
+    res = Py_None;
+
+exit:
+    Py_CLEAR(test_c_thread.callback);
+    if (test_c_thread.start_event)
+        PyThread_free_lock(test_c_thread.start_event);
+    if (test_c_thread.exit_event)
+        PyThread_free_lock(test_c_thread.exit_event);
+    return res;
+}
+#endif   /* WITH_THREAD */
+
+
 static PyMethodDef TestMethods[] = {
     {"raise_exception",         raise_exception,                 METH_VARARGS},
     {"test_config",             (PyCFunction)test_config,        METH_NOARGS},
@@ -1745,6 +1835,10 @@
     {"make_exception_with_doc", (PyCFunction)make_exception_with_doc,
      METH_VARARGS | METH_KEYWORDS},
     {"sequence_delitem", (PyCFunction)sequence_delitem, METH_VARARGS},
+#ifdef WITH_THREAD
+    {"call_in_temporary_c_thread", call_in_temporary_c_thread, METH_O,
+     PyDoc_STR("set_error_class(error_class) -> None")},
+#endif
     {NULL, NULL} /* sentinel */
 };