diff --git a/Doc/tutorial/controlflow.rst b/Doc/tutorial/controlflow.rst
index 813c828..8453796 100644
--- a/Doc/tutorial/controlflow.rst
+++ b/Doc/tutorial/controlflow.rst
@@ -78,6 +78,9 @@
    >>> words
    ['defenestrate', 'cat', 'window', 'defenestrate']
 
+With ``for w in words:``, the example would attempt to create an infinite list,
+inserting ``defenestrate`` over and over again.
+
 
 .. _tut-range: