diff --git a/CHANGES.rst b/CHANGES.rst
index 390620d81c..f3d213ee40 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -20,6 +20,8 @@ Bugfixes
 - Fix handling of non-ASCII characters in URLs on Python 2 introduced on 4.0b5.
   (`#380 <https://github.com/zopefoundation/Zope/pull/380>`_)
 
+- Fix zodbupdate conversion of ``OFS.Image.Pdata`` objects.
+
 
 4.0b6 (2018-10-11)
 ------------------
diff --git a/src/OFS/__init__.py b/src/OFS/__init__.py
index c182ef09e2..10e765caf6 100644
--- a/src/OFS/__init__.py
+++ b/src/OFS/__init__.py
@@ -9,6 +9,7 @@
     'OFS.Image File title': 'utf-8',
     'OFS.Image Image title': 'utf-8',
     'OFS.Image Pdata title': 'utf-8',
+    'OFS.Image Pdata data': 'binary',
     'OFS.OrderedFolder OrderedFolder title': 'utf-8',
     'OFS.userfolder UserFolder title': 'utf-8',
 }