#9730: fix example.
diff --git a/Doc/library/base64.rst b/Doc/library/base64.rst
index e282ea0..0802e6c 100644
--- a/Doc/library/base64.rst
+++ b/Doc/library/base64.rst
@@ -157,12 +157,12 @@
 An example usage of the module:
 
    >>> import base64
-   >>> encoded = base64.b64encode('data to be encoded')
+   >>> encoded = base64.b64encode(b'data to be encoded')
    >>> encoded
    b'ZGF0YSB0byBiZSBlbmNvZGVk'
    >>> data = base64.b64decode(encoded)
    >>> data
-   'data to be encoded'
+   b'data to be encoded'
 
 
 .. seealso::