diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -854,7 +854,7 @@
                 ui.status(_('changeset %d:%s: %s\n') % (ctx, ctx, transition))
                 hbisect.checkstate(state)
                 # bisect
-                nodes, changesets, bgood = hbisect.bisect(repo.changelog, state)
+                nodes, changesets, bgood = hbisect.bisect(repo, state)
                 # update to next check
                 node = nodes[0]
                 mayupdate(repo, node, show_stats=False)
@@ -867,7 +867,7 @@
     hbisect.checkstate(state)
 
     # actually bisect
-    nodes, changesets, good = hbisect.bisect(repo.changelog, state)
+    nodes, changesets, good = hbisect.bisect(repo, state)
     if extend:
         if not changesets:
             extendnode = hbisect.extendrange(repo, state, nodes, good)
diff --git a/mercurial/hbisect.py b/mercurial/hbisect.py
--- a/mercurial/hbisect.py
+++ b/mercurial/hbisect.py
@@ -21,7 +21,7 @@
     error,
 )
 
-def bisect(changelog, state):
+def bisect(repo, state):
     """find the next node (if any) for testing during a bisect search.
     returns a (nodes, number, good) tuple.
 
@@ -32,6 +32,7 @@
     if searching for a first bad one.
     """
 
+    changelog = repo.changelog
     clparents = changelog.parentrevs
     skip = set([changelog.rev(n) for n in state['skip']])