diff -r 3ee036c6f834 -r fca9c63f160e mercurial/cmdutil.py
--- a/mercurial/cmdutil.py	Thu Jun 10 14:47:14 2021 -0700
+++ b/mercurial/cmdutil.py	Thu Jun 10 14:55:10 2021 -0700
@@ -2783,6 +2783,7 @@
 
 
 def amend(ui, repo, old, extra, pats, opts):
+    opts = pycompat.byteskwargs(opts)
     # avoid cycle context -> subrepo -> cmdutil
     from . import context