builtin -> built-in.
diff --git a/Doc/library/numbers.rst b/Doc/library/numbers.rst
index b0d55a7..580127c 100644
--- a/Doc/library/numbers.rst
+++ b/Doc/library/numbers.rst
@@ -24,7 +24,7 @@
.. class:: Complex
Subclasses of this type describe complex numbers and include the operations
- that work on the builtin :class:`complex` type. These are: conversions to
+ that work on the built-in :class:`complex` type. These are: conversions to
:class:`complex` and :class:`bool`, :attr:`.real`, :attr:`.imag`, ``+``,
``-``, ``*``, ``/``, :func:`abs`, :meth:`conjugate`, ``==``, and ``!=``. All
except ``-`` and ``!=`` are abstract.