Fix, thanks to Nick.
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index 752bd50..08566fa 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -120,7 +120,7 @@
.. function:: bytearray([arg[, encoding[, errors]]])
- Return a new array of bytes. The :class:`bytearray` type is an immutable
+ Return a new array of bytes. The :class:`bytearray` type is a mutable
sequence of integers in the range 0 <= x < 256. It has most of the usual
methods of mutable sequences, described in :ref:`typesseq-mutable`, as well
as most methods that the :class:`str` type has, see :ref:`bytes-methods`.