diff --git a/hgext/blackbox.py b/hgext/blackbox.py
--- a/hgext/blackbox.py
+++ b/hgext/blackbox.py
@@ -80,9 +80,6 @@
             self._bbinlog = False
             self._bbrepo = getattr(src, '_bbrepo', None)
 
-        def copy(self):
-            return self.__class__(self)
-
         @property
         def _bbvfs(self):
             repo = getattr(self, '_bbrepo', None)