--- a/hgext/rebase.py	Tue Mar 23 14:15:40 2021 -0700
+++ b/hgext/rebase.py	Tue Mar 23 22:48:27 2021 -0700
@@ -441,8 +441,10 @@
         # Calculate self.obsolete_* sets
         self._handleskippingobsolete()
 
-        rebaseset = destmap.keys()
         if not self.keepf:
+            rebaseset = set(destmap.keys())
+            rebaseset -= set(self.obsolete_with_successor_in_destination)
+            rebaseset -= self.obsolete_with_successor_in_rebase_set
             try:
                 rewriteutil.precheck(self.repo, rebaseset, action=b'rebase')
             except error.Abort as e: