Make it clear that PyNumber_AsSsize_t() returns -1 on error.
diff --git a/Doc/c-api/number.rst b/Doc/c-api/number.rst
index eda722d..090fc64 100644
--- a/Doc/c-api/number.rst
+++ b/Doc/c-api/number.rst
@@ -249,7 +249,9 @@
.. c:function:: Py_ssize_t PyNumber_AsSsize_t(PyObject *o, PyObject *exc)
Returns *o* converted to a Py_ssize_t value if *o* can be interpreted as an
- integer. If *o* can be converted to a Python int but the attempt to
+ integer. If the call fails, an exception is raised and -1 is returned.
+
+ If *o* can be converted to a Python int but the attempt to
convert to a Py_ssize_t value would raise an :exc:`OverflowError`, then the
*exc* argument is the type of exception that will be raised (usually
:exc:`IndexError` or :exc:`OverflowError`). If *exc* is *NULL*, then the