Update padding docs
diff --git a/docs/hazmat/primitives/padding.rst b/docs/hazmat/primitives/padding.rst
index 83154c0..d23f31b 100644
--- a/docs/hazmat/primitives/padding.rst
+++ b/docs/hazmat/primitives/padding.rst
@@ -66,7 +66,16 @@
:param bytes data: The data you wish to pass into the context.
:return bytes: Returns the data that was padded or unpadded.
+ :raises cryptography.exceptions.AlreadyFinalized: See :meth:`finalize`.
.. method:: finalize()
+ Finalize the current context and return the rest of the data.
+
+ After ``finalize`` has been called this object can no longer be used;
+ :meth:`update` and :meth:`finalize` will raise an
+ :class:`~cryptography.exceptions.AlreadyFinalized` exception.
+
:return bytes: Returns the remainder of the data.
+ :raises ValueError: When trying to remove padding from incorrectly
+ padded data.