diff --git a/mercurial/error.py b/mercurial/error.py
--- a/mercurial/error.py
+++ b/mercurial/error.py
@@ -272,8 +272,6 @@
         else:
             Exception.__init__(self, message)
 
-    __bytes__ = _tobytes
-
     def format(self):
         from .i18n import _