diff --git a/docs/handbook/writing-your-own-file-decoder.rst b/docs/handbook/writing-your-own-file-decoder.rst
index caf9dc07e..10833a53e 100644
--- a/docs/handbook/writing-your-own-file-decoder.rst
+++ b/docs/handbook/writing-your-own-file-decoder.rst
@@ -1,10 +1,13 @@
 Writing your own file decoder
 =============================
 
-The Python Imaging Library uses a plug-in model which allows you to add your
-own decoders to the library, without any changes to the library itself. Such
-plug-ins have names like :file:`XxxImagePlugin.py`, where ``Xxx`` is a unique
-format name (usually an abbreviation).
+The Python Imaging Library uses a plug-in model which allows you to
+add your own decoders to the library, without any changes to the
+library itself. Such plug-ins usually have names like
+:file:`XxxImagePlugin.py`, where ``Xxx`` is a unique format name
+(usually an abbreviation).
+
+.. warning:: Pillow >= 2.1.0 no longer automatically imports any file in the Python path with a name ending in :file:`ImagePlugin.py`.  You will need to import your decoder manually. 
 
 A decoder plug-in should contain a decoder class, based on the
 :py:class:`PIL.ImageFile.ImageFile` base class. This class should provide an
diff --git a/docs/porting-pil-to-pillow.rst b/docs/porting-pil-to-pillow.rst
index 93bc672af..a58baac39 100644
--- a/docs/porting-pil-to-pillow.rst
+++ b/docs/porting-pil-to-pillow.rst
@@ -15,3 +15,9 @@ to this::
 The :py:mod:`_imaging` module has been moved. You can now import it like this::
 
     from PIL.Image import core as _imaging
+
+The image plugin loading mechanisim has changed. Pillow no longer
+automatically imports any file in the Python path with a name ending
+in :file:`ImagePlugin.py`. You will need to import your image plugin
+manually.
+