Issue #4129: int -> Py_ssize_t documentation.
diff --git a/Doc/c-api/sequence.rst b/Doc/c-api/sequence.rst
index c934a1d..0b22090 100644
--- a/Doc/c-api/sequence.rst
+++ b/Doc/c-api/sequence.rst
@@ -178,6 +178,10 @@
    Return the *i*th element of *o*, assuming that *o* was returned by
    :cfunc:`PySequence_Fast`, *o* is not *NULL*, and that *i* is within bounds.
 
+   .. versionchanged:: 2.5
+      This function used an :ctype:`int` type for *i*. This might require
+      changes in your code for properly supporting 64-bit systems.
+
 
 .. cfunction:: PyObject** PySequence_Fast_ITEMS(PyObject *o)
 
@@ -200,6 +204,10 @@
 
    .. versionadded:: 2.3
 
+   .. versionchanged:: 2.5
+      This function used an :ctype:`int` type for *i*. This might require
+      changes in your code for properly supporting 64-bit systems.
+
 
 .. cfunction:: Py_ssize_t PySequence_Fast_GET_SIZE(PyObject *o)