diff --git a/Doc/c-api/arg.rst b/Doc/c-api/arg.rst
index d4dda7c..a171ac7 100644
--- a/Doc/c-api/arg.rst
+++ b/Doc/c-api/arg.rst
@@ -260,9 +260,11 @@
 ``n`` (:class:`int`) [Py_ssize_t]
    Convert a Python integer to a C :c:type:`Py_ssize_t`.
 
-``c`` (:class:`bytes` of length 1) [char]
-   Convert a Python byte, represented as a :class:`bytes` object of length 1,
-   to a C :c:type:`char`.
+``c`` (:class:`bytes` or :class:`bytearray` of length 1) [char]
+   Convert a Python byte, represented as a :class:`bytes` or
+   :class:`bytearray` object of length 1, to a C :c:type:`char`.
+
+   .. versionchanged:: 3.3 Allow :class:`bytearray` objects
 
 ``C`` (:class:`str` of length 1) [int]
    Convert a Python character, represented as a :class:`str` object of