diff -r 04cdb442a892 -r 290c29df1915 mercurial/bundle2.py
--- a/mercurial/bundle2.py	Wed May 25 11:53:34 2022 +0200
+++ b/mercurial/bundle2.py	Wed May 18 10:39:45 2022 +0100
@@ -1692,7 +1692,7 @@
         raise error.ProgrammingError(b'unknown bundle type: %s' % bundletype)
 
     caps = {}
-    if b'obsolescence' in opts:
+    if opts.get(b'obsolescence', False):
         caps[b'obsmarkers'] = (b'V1',)
     bundle = bundle20(ui, caps)
     bundle.setcompression(compression, compopts)