Fix markup.
diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
index 250c842..14a7afd 100644
--- a/Doc/library/itertools.rst
+++ b/Doc/library/itertools.rst
@@ -760,7 +760,7 @@
Note, many of the above recipes can be optimized by replacing global lookups
with local variables defined as default values. For example, the
-*dotproduct* recipe can be written as:
+*dotproduct* recipe can be written as::
def dotproduct(vec1, vec2, sum=sum, imap=imap, mul=operator.mul):
return sum(imap(mul, vec1, vec2))