diff --git a/Doc/library/datetime.rst b/Doc/library/datetime.rst
index e0b28d7cb978d9..e387496b9fc624 100644
--- a/Doc/library/datetime.rst
+++ b/Doc/library/datetime.rst
@@ -1364,14 +1364,8 @@ Instance methods:
 
    Return POSIX timestamp corresponding to the :class:`.datetime`
    instance. The return value is a :class:`float` similar to that
-   returned by :func:`time.time`.
-
-   Naive :class:`.datetime` instances are assumed to represent local
-   time and this method relies on the platform C :c:func:`mktime`
-   function to perform the conversion. Since :class:`.datetime`
-   supports wider range of values than :c:func:`mktime` on many
-   platforms, this method may raise :exc:`OverflowError` for times far
-   in the past or far in the future.
+   returned by :func:`time.time`. Raises :exc:`OSError` for times far in the
+   past or far in the future.
 
    For aware :class:`.datetime` instances, the return value is computed
    as::