diff -r 70a7478c33de -r 597b071a0e0d mercurial/subrepo.py
--- a/mercurial/subrepo.py	Sat Dec 13 14:26:38 2014 -0500
+++ b/mercurial/subrepo.py	Sat Dec 13 19:23:30 2014 -0500
@@ -496,7 +496,7 @@
         '''
         pass
 
-    def forget(self, ui, match, prefix):
+    def forget(self, match, prefix):
         return ([], [])
 
     def removefiles(self, ui, matcher, prefix, after, force, subrepos):
@@ -850,8 +850,8 @@
         return ctx.walk(match)
 
     @annotatesubrepoerror
-    def forget(self, ui, match, prefix):
-        return cmdutil.forget(ui, self._repo, match,
+    def forget(self, match, prefix):
+        return cmdutil.forget(self.ui, self._repo, match,
                               os.path.join(prefix, self._path), True)
 
     @annotatesubrepoerror