Issue #13783: the PEP 380 implementation no longer expands the public C API
diff --git a/Python/ceval.c b/Python/ceval.c
index b3ec013..7e9318b 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1852,7 +1852,7 @@
                 PyObject *val;
                 x = POP(); /* Remove iter from stack */
                 Py_DECREF(x);
-                err = PyGen_FetchStopIterationValue(&val);
+                err = _PyGen_FetchStopIterationValue(&val);
                 if (err < 0) {
                     x = NULL;
                     break;