diff --git a/Include/pyerrors.h b/Include/pyerrors.h
index fb9ce91..58a3df7 100644
--- a/Include/pyerrors.h
+++ b/Include/pyerrors.h
@@ -60,7 +60,10 @@
 
 PyAPI_FUNC(void) PyErr_SetNone(PyObject *);
 PyAPI_FUNC(void) PyErr_SetObject(PyObject *, PyObject *);
-PyAPI_FUNC(void) PyErr_SetString(PyObject *, const char *);
+PyAPI_FUNC(void) PyErr_SetString(
+    PyObject *exception,
+    const char *string   /* decoded from utf-8 */
+    );
 PyAPI_FUNC(PyObject *) PyErr_Occurred(void);
 PyAPI_FUNC(void) PyErr_Clear(void);
 PyAPI_FUNC(void) PyErr_Fetch(PyObject **, PyObject **, PyObject **);
@@ -177,7 +180,9 @@
 PyAPI_FUNC(PyObject *) PyErr_SetFromErrnoWithFilenameObject(
     PyObject *, PyObject *);
 PyAPI_FUNC(PyObject *) PyErr_SetFromErrnoWithFilename(
-    PyObject *, const char *);
+    PyObject *exc,
+    const char *filename   /* decoded from the filesystem encoding */
+    );
 #ifdef MS_WINDOWS
 PyAPI_FUNC(PyObject *) PyErr_SetFromErrnoWithUnicodeFilename(
     PyObject *, const Py_UNICODE *);