--- a/hgext/rebase.py	Sun Nov 06 23:35:33 2011 +0100
+++ b/hgext/rebase.py	Tue Nov 08 17:09:48 2011 +0100
@@ -215,6 +215,7 @@
                 originalwd, target, state = result
                 if collapsef:
                     targetancestors = set(repo.changelog.ancestors(target))
+                    targetancestors.add(target)
                     external = checkexternal(repo, state, targetancestors)
 
         if keepbranchesf: