diff --git a/hgext/phabricator.py b/hgext/phabricator.py
--- a/hgext/phabricator.py
+++ b/hgext/phabricator.py
@@ -50,6 +50,7 @@
 from mercurial.node import bin, nullid
 from mercurial.i18n import _
 from mercurial.pycompat import getattr
+from mercurial.thirdparty import attr
 from mercurial import (
     cmdutil,
     context,
@@ -465,6 +466,21 @@
     BINARY = 3
 
 
+@attr.s
+class phabhunk(dict):
+    """Represents a Differential hunk, which is owned by a Differential change
+    """
+
+    oldOffset = attr.ib(default=0)  # camelcase-required
+    oldLength = attr.ib(default=0)  # camelcase-required
+    newOffset = attr.ib(default=0)  # camelcase-required
+    newLength = attr.ib(default=0)  # camelcase-required
+    corpus = attr.ib(default='')
+    # These get added to the phabchange's equivalents
+    addLines = attr.ib(default=0)  # camelcase-required
+    delLines = attr.ib(default=0)  # camelcase-required
+
+
 def creatediff(ctx):
     """create a Differential Diff"""
     repo = ctx.repo()