#4975: fix bytes/str issue.
diff --git a/Doc/library/base64.rst b/Doc/library/base64.rst
index 35b61ae..48d24db 100644
--- a/Doc/library/base64.rst
+++ b/Doc/library/base64.rst
@@ -154,7 +154,7 @@
    >>> import base64
    >>> encoded = base64.b64encode('data to be encoded')
    >>> encoded
-   'ZGF0YSB0byBiZSBlbmNvZGVk'
+   b'ZGF0YSB0byBiZSBlbmNvZGVk'
    >>> data = base64.b64decode(encoded)
    >>> data
    'data to be encoded'