diff --git a/mercurial/changegroup.py b/mercurial/changegroup.py
--- a/mercurial/changegroup.py
+++ b/mercurial/changegroup.py
@@ -707,15 +707,14 @@
                                 lookuplinknode, units=_('manifests')):
             yield chunk
 
-    def _packtreemanifests(self, dir, mfnodes, lookuplinknode):
-        """Version of _packmanifests that operates on directory manifests.
+    def _packmanifestsdirheader(self, dir, mfnodes, lookuplinknode):
+        """Version of _packmanifests that encodes the directory name.
 
         Encodes the directory name in the output so multiple manifests
         can be sent.
         """
-        assert self.version == b'03'
-
         if dir:
+            assert self.version == b'03'
             yield self._fileheader(dir)
 
         # TODO violates storage abstractions by assuming revlogs.
@@ -902,7 +901,7 @@
                 return clnode
             return lookupmflinknode
 
-        fn = (self._packtreemanifests if self._sendtreemanifests
+        fn = (self._packmanifestsdirheader if self._sendtreemanifests
               else self._packmanifests)
         size = 0
         while tmfnodes: