diff --git a/pushrebase.py b/pushrebase.py
index 2a32057670..b5364eff75 100644
--- a/pushrebase.py
+++ b/pushrebase.py
@@ -55,6 +55,9 @@ def validaterevset(repo, revset):
     if repo.revs('%r and merge()', revset):
         raise util.Abort(_('cannot rebase merge changesets'))
 
+    if repo.revs('%r and obsolete()', revset):
+        raise util.Abort(_('cannot rebase obsolete changesets'))
+
     tails = repo.revs('%r and ancestor(%r)', revset, revset)
     if not tails:
         raise util.Abort(_('cannot rebase unrelated changesets'))