Migrate to Sphinx 1.0 C language constructs.
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst
index f6a6f80..f8f0455 100644
--- a/Doc/reference/expressions.rst
+++ b/Doc/reference/expressions.rst
@@ -651,7 +651,7 @@
An implementation may provide built-in functions whose positional parameters
do not have names, even if they are 'named' for the purpose of documentation,
and which therefore cannot be supplied by keyword. In CPython, this is the
- case for functions implemented in C that use :cfunc:`PyArg_ParseTuple` to
+ case for functions implemented in C that use :c:func:`PyArg_ParseTuple` to
parse their arguments.
If there are more positional arguments than there are formal parameter slots, a