diff --git a/CHANGES.txt b/CHANGES.txt
index 02b4949..1908d9e 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -26,6 +26,15 @@ Features
 - Allow localization of error messages returned by ``colander.Invalid.asdict``
   by adding an optional ``translate`` callable argument.
 
+Backwards Incompatibilities
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- ``SchemaNode.deserialize`` will now raise an
+  ``UnboundDeferredError`` if the node has an unbound deferred
+  validator.  Previously, deferred validators were silently ignored.
+  See https://github.com/Pylons/colander/issues/47
+
+
 1.0b1 (2013-09-01)
 ------------------
 
diff --git a/docs/api.rst b/docs/api.rst
index 8f972bd..51b6d75 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -48,6 +48,9 @@ Exceptions
        from a widget as the value which should be redisplayed when an
        error is shown.
 
+  .. autoclass:: UnboundDeferredError
+
+
 Validators
 ~~~~~~~~~~
 
diff --git a/docs/binding.rst b/docs/binding.rst
index 61e5efa..94340c2 100644
--- a/docs/binding.rst
+++ b/docs/binding.rst
@@ -248,7 +248,8 @@ If you use a schema with deferred ``validator``, ``missing`` or
 ``default`` attributes, but you use it to perform serialization and
 deserialization without calling its ``bind`` method:
 
-- If ``validator`` is deferred, no validation will be performed.
+- If ``validator`` is deferred, :meth:`~colander.SchemaNode.deserialize` will
+  raise an :exc:`~colander.UnboundDeferredError`.
 
 - If ``missing`` is deferred, the field will be considered *required*.