diff --git a/can/__init__.py b/can/__init__.py
index f21ffcc09..037c407f0 100644
--- a/can/__init__.py
+++ b/can/__init__.py
@@ -8,7 +8,7 @@
 import logging
 from typing import Dict, Any
 
-__version__ = "4.0.0-dev.2"
+__version__ = "4.0.0-rc.0"
 
 log = logging.getLogger("can")
 
diff --git a/doc/history.rst b/doc/history.rst
index caed67baa..659f18dda 100644
--- a/doc/history.rst
+++ b/doc/history.rst
@@ -49,7 +49,7 @@ The CANalyst-II interface was contributed by Shaoyu Meng in 2018.
 Support for CAN within Python
 -----------------------------
 
-Python natively supports the CAN protocol from version 3.3 on, if running on Linux:
+Python natively supports the CAN protocol from version 3.3 on, if running on Linux (with a sufficiently new kernel):
 
 ==============  ==============================================================  ====
 Python version  Feature                                                         Link
@@ -58,4 +58,5 @@ Python version  Feature
 3.4             Broadcast Management (BCM) commands are natively supported      `Docs <https://docs.python.org/3/library/socket.html#socket.CAN_BCM>`__
 3.5             CAN FD support                                                  `Docs <https://docs.python.org/3/library/socket.html#socket.CAN_RAW_FD_FRAMES>`__
 3.7             Support for CAN ISO-TP                                          `Docs <https://docs.python.org/3/library/socket.html#socket.CAN_ISOTP>`__
+3.9             Native support for joining CAN filters                          `Docs <https://docs.python.org/3/library/socket.html#socket.CAN_RAW_JOIN_FILTERS>`__
 ==============  ==============================================================  ====
diff --git a/doc/pycanlib.pml b/doc/pycanlib.pml
index 0ddcf25e5..907fadabb 100644
--- a/doc/pycanlib.pml
+++ b/doc/pycanlib.pml
@@ -1,4 +1,4 @@
-/* This promela model was used to verify the concurrent design of the bus object. */
+/* This promela model was used to verify a past design of the bus object. */
 
 bool lock = false;