diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
index 1eb554a40ae..7099fa031b9 100644
--- a/Doc/library/itertools.rst
+++ b/Doc/library/itertools.rst
@@ -705,9 +705,9 @@ which incur interpreter overhead.
        next(b, None)
        return zip(a, b)
 
-   def grouper(n, iterable, fillvalue=None):
+   def grouper(iterable, n, fillvalue=None):
        "Collect data into fixed-length chunks or blocks"
-       # grouper(3, 'ABCDEFG', 'x') --> ABC DEF Gxx"
+       # grouper('ABCDEFG', 3, 'x') --> ABC DEF Gxx"
        args = [iter(iterable)] * n
        return zip_longest(*args, fillvalue=fillvalue)