diff --git a/scripts/sync-hg-repos-from-manifest b/scripts/sync-hg-repos-from-manifest
--- a/scripts/sync-hg-repos-from-manifest
+++ b/scripts/sync-hg-repos-from-manifest
@@ -49,8 +49,6 @@
         if not os.path.exists(path):
             is_clone = True
             args = [HG, 'init', path]
-            if 'generaldelta' in requires:
-                args.extend(['--config', 'format.generaldelta=true'])
 
             print('creating empty repo: %s' % path)
             subprocess.check_output(args, cwd='/', stderr=subprocess.STDOUT)