diff --git a/mercurial/context.py b/mercurial/context.py
--- a/mercurial/context.py
+++ b/mercurial/context.py
@@ -30,7 +30,6 @@ from . import (
     error,
     fileset,
     match as matchmod,
-    mdiff,
     obsolete as obsmod,
     patch,
     pathutil,
@@ -304,10 +303,7 @@ class basectx(object):
         if ctx2 is not None:
             ctx2 = self._repo[ctx2]
 
-        if isinstance(opts, mdiff.diffopts):
-            diffopts = opts
-        else:
-            diffopts = patch.diffopts(self._repo.ui, opts)
+        diffopts = opts
         return patch.diff(self._repo, ctx2, self, match=match, changes=changes,
                           opts=diffopts, losedatafn=losedatafn, prefix=prefix,
                           relroot=relroot, copy=copy,