diff -r ee91966aec0f -r f4c325bf80fc mercurial/wireprotov1server.py
--- a/mercurial/wireprotov1server.py	Wed Mar 03 14:00:45 2021 +0100
+++ b/mercurial/wireprotov1server.py	Wed Mar 03 12:30:23 2021 +0100
@@ -109,7 +109,7 @@
     4. server.bundle1
     """
     ui = repo.ui
-    gd = b'generaldelta' in repo.requirements
+    gd = requirementsmod.GENERALDELTA_REQUIREMENT in repo.requirements
 
     if gd:
         v = ui.configbool(b'server', b'bundle1gd.%s' % action)