builtin -> built-in.
diff --git a/Doc/c-api/buffer.rst b/Doc/c-api/buffer.rst
index 3f13e74..4824358 100644
--- a/Doc/c-api/buffer.rst
+++ b/Doc/c-api/buffer.rst
@@ -31,7 +31,7 @@
returning data from the target object.
Starting from version 1.6, Python has been providing Python-level buffer
-objects and a C-level buffer API so that any builtin or used-defined type can
+objects and a C-level buffer API so that any built-in or used-defined type can
expose its characteristics. Both, however, have been deprecated because of
various shortcomings, and have been officially removed in Python 3.0 in favour
of a new C-level buffer API and a new Python-level object named