diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -1133,7 +1133,7 @@
         fm.startitem()
         fm.write('branch', '%s', tag, label=label)
         rev = ctx.rev()
-        padsize = max(31 - len(str(rev)) - encoding.colwidth(tag), 0)
+        padsize = max(31 - len("%d" % rev) - encoding.colwidth(tag), 0)
         fmt = ' ' * padsize + ' %d:%s'
         fm.condwrite(not ui.quiet, 'rev node', fmt, rev, hexfunc(ctx.node()),
                      label='log.changeset changeset.%s' % ctx.phasestr())