diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -481,7 +481,7 @@ class rebaseruntime(object):
                         ui.setconfig('ui', 'forcemerge', opts.get('tool', ''),
                                      'rebase')
                         stats = rebasenode(repo, rev, p1, base, self.state,
-                                           self.collapsef, dest)
+                                           self.collapsef, dest, wctx=self.wctx)
                         if stats and stats[3] > 0:
                             if self.wctx.isinmemory():
                                 raise error.InMemoryMergeConflictsError()
@@ -992,7 +992,7 @@ def concludenode(repo, rev, p1, p2, comm
         repo.dirstate.setbranch(repo[newnode].branch())
         return newnode
 
-def rebasenode(repo, rev, p1, base, state, collapse, dest):
+def rebasenode(repo, rev, p1, base, state, collapse, dest, wctx):
     'Rebase a single revision rev on top of p1 using base as merge ancestor'
     # Merge phase
     # Update to destination and merge it with local