diff --git a/README.rst b/README.rst
index b5989c6..b459ec2 100644
--- a/README.rst
+++ b/README.rst
@@ -101,7 +101,11 @@ compile this extension like this::
     python setup.py build
 
 Note that you need the development headers for your version of Python installed,
-look for a package named 'python-dev', 'python-devel' or similar.
+look for a package named 'python-dev', 'python-devel' or similar. Also, some
+Python distributions do not install "Imaging.h" and "ImPlatform.h" properly. If
+you get errors complaining about them, you can get them from the PIL source, or
+at <http://svn.effbot.org/public/tags/pil-1.1.7/libImaging/>. Just put them in
+the same directory as "_composite.c".
 
 Running
 -------