Add a note that the first argument to read_util was called `terminator` in previous versions
diff --git a/documentation/pyserial_api.rst b/documentation/pyserial_api.rst
index efd82c1..12a7765 100644
--- a/documentation/pyserial_api.rst
+++ b/documentation/pyserial_api.rst
@@ -173,6 +173,9 @@
Returns an instance of :class:`bytes` when available (Python 2.6
and newer) and :class:`str` otherwise.
+ .. versionchanged:: 3.5
+ First argument was called ``terminator`` in previous versions.
+
.. method:: write(data)
:param data: Data to send.