diff --git a/contrib/python3-whitelist b/contrib/python3-whitelist
--- a/contrib/python3-whitelist
+++ b/contrib/python3-whitelist
@@ -25,6 +25,7 @@ test-bookmarks-merge.t
 test-bookmarks-rebase.t
 test-bookmarks-strip.t
 test-bookmarks.t
+test-branch-change.t
 test-branch-option.t
 test-branch-tag-confict.t
 test-branches.t
diff --git a/mercurial/scmutil.py b/mercurial/scmutil.py
--- a/mercurial/scmutil.py
+++ b/mercurial/scmutil.py
@@ -689,7 +689,8 @@ def cleanupnodes(repo, replacements, ope
                 continue
             from . import bookmarks # avoid import cycle
             repo.ui.debug('moving bookmarks %r from %s to %s\n' %
-                          (oldbmarks, hex(oldnode), hex(newnode)))
+                          (util.rapply(pycompat.maybebytestr, oldbmarks),
+                           hex(oldnode), hex(newnode)))
             # Delete divergent bookmarks being parents of related newnodes
             deleterevs = repo.revs('parents(roots(%ln & (::%n))) - parents(%n)',
                                    allnewnodes, newnode, oldnode)