#4827: fix callback example.
diff --git a/Doc/library/optparse.rst b/Doc/library/optparse.rst
index 604ac7f..4ef2ba7 100644
--- a/Doc/library/optparse.rst
+++ b/Doc/library/optparse.rst
@@ -1511,7 +1511,7 @@
 records that the option was seen::
 
    def record_foo_seen(option, opt_str, value, parser):
-       parser.saw_foo = True
+       parser.values.saw_foo = True
 
    parser.add_option("--foo", action="callback", callback=record_foo_seen)