diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
index 0ee93ed..c9298fa 100644
--- a/Doc/library/itertools.rst
+++ b/Doc/library/itertools.rst
@@ -159,7 +159,7 @@ loops that truncate the stream.
    single iterable argument that is evaluated lazily.  Equivalent to::
 
       @classmethod
-      def from_iterable(iterables):
+      def from_iterable(cls, iterables):
           # chain.from_iterable(['ABC', 'DEF']) --> A B C D E F
           for it in iterables:
               for element in it: