--- a/mercurial/revlogutils/deltas.py	Tue Oct 10 11:13:24 2023 +0200
+++ b/mercurial/revlogutils/deltas.py	Tue Oct 10 11:16:07 2023 +0200
@@ -608,7 +608,7 @@
 
     textlen = revinfo.textlen
     defaultmax = textlen * 4
-    maxdist = revlog._maxdeltachainspan
+    maxdist = revlog.delta_config.max_deltachain_span
     if not maxdist:
         maxdist = deltainfo.distance  # ensure the conditional pass
     maxdist = max(maxdist, defaultmax)