diff -r d5d1edf66091 -r 162b81e65e60 hgext/phabricator.py
--- a/hgext/phabricator.py	Sun Oct 06 17:21:26 2019 +0100
+++ b/hgext/phabricator.py	Sat Oct 12 14:41:59 2019 +0100
@@ -518,7 +518,7 @@
     def addhunk(self, hunk):
         if not isinstance(hunk, phabhunk):
             raise error.Abort(b'phabchange.addhunk only takes phabhunks')
-        self.hunks.append(hunk)
+        self.hunks.append(pycompat.byteskwargs(attr.asdict(hunk)))
         # It's useful to include these stats since the Phab web UI shows them,
         # and uses them to estimate how large a change a Revision is. Also used
         # in email subjects for the [+++--] bit.
@@ -549,7 +549,9 @@
     def addchange(self, change):
         if not isinstance(change, phabchange):
             raise error.Abort(b'phabdiff.addchange only takes phabchanges')
-        self.changes[change.currentPath] = change
+        self.changes[change.currentPath] = pycompat.byteskwargs(
+            attr.asdict(change)
+        )
 
 
 def maketext(pchange, ctx, fname):