@@ -1425,6 +1425,12 @@ PyAPI_FUNC(PyObject*) PyUnicode_EncodeCharmap(
                                    (unicode ordinal -> char ordinal) */
     const char *errors          /* error handling */
     );
+PyAPI_FUNC(PyObject*) _PyUnicode_EncodeCharmap(
+    PyObject *unicode,          /* Unicode object */
+    PyObject *mapping,          /* character mapping
+                                   (unicode ordinal -> char ordinal) */
+    const char *errors          /* error handling */
+    );
 #endif
 
 /* Translate a Py_UNICODE buffer of the given length by applying a
 
@@ -992,11 +992,7 @@ charmap_encode(PyObject *self,
     str = PyUnicode_FromObject(str);
     if (str == NULL)
         return NULL;
-    v = codec_tuple(PyUnicode_EncodeCharmap(
-                               PyUnicode_AS_UNICODE(str),
-                               PyUnicode_GET_SIZE(str),
-                               mapping,
-                               errors),
+    v = codec_tuple(_PyUnicode_EncodeCharmap(str, mapping, errors),
                     PyUnicode_GET_SIZE(str));
     Py_DECREF(str);
     return v;