diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
index ce0d7cbb2e4276..2435f074f052d0 100644
--- a/Doc/library/stdtypes.rst
+++ b/Doc/library/stdtypes.rst
@@ -2163,6 +2163,8 @@ expression support in the :mod:`re` module).
 
    .. doctest::
 
+      >>> 'spam, spam, spam'.index('spam')
+      0
       >>> 'spam, spam, spam'.index('eggs')
       Traceback (most recent call last):
         File "<python-input-0>", line 1, in <module>