diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -474,7 +474,7 @@
                         )
 
         # Calculate self.obsoletenotrebased
-        obsrevs = _filterobsoleterevs(self.repo, self.state)
+        obsrevs = {r for r in self.state if self.repo[r].obsolete()}
         self._handleskippingobsolete(obsrevs, self.destmap)
 
         # Keep track of the active bookmarks in order to reset them later
@@ -2184,11 +2184,6 @@
     return ret
 
 
-def _filterobsoleterevs(repo, revs):
-    """returns a set of the obsolete revisions in revs"""
-    return {r for r in revs if repo[r].obsolete()}
-
-
 def _computeobsoletenotrebased(repo, rebaseobsrevs, destmap):
     """Return (obsoletenotrebased, obsoletewithoutsuccessorindestination).