diff --git a/mercurial/changelog.py b/mercurial/changelog.py
--- a/mercurial/changelog.py
+++ b/mercurial/changelog.py
@@ -404,12 +404,6 @@
         self.filteredrevs = frozenset()
         self._copiesstorage = opener.options.get(b'copies-storage')
 
-    def flags(self, rev):
-        """filtered version of revlog.flags"""
-        if rev in self.filteredrevs:
-            raise error.FilteredIndexError(rev)
-        return super(changelog, self).flags(rev)
-
     def delayupdate(self, tr):
         b"delay visibility of index updates to other readers"
 
diff --git a/mercurial/repoview.py b/mercurial/repoview.py
--- a/mercurial/repoview.py
+++ b/mercurial/repoview.py
@@ -324,6 +324,12 @@
                 raise error.FilteredIndexError(rev)
             return super(filteredchangelog, self).parentrevs(rev)
 
+        def flags(self, rev):
+            """filtered version of revlog.flags"""
+            if rev in self.filteredrevs:
+                raise error.FilteredIndexError(rev)
+            return super(filteredchangelog, self).flags(rev)
+
     cl.__class__ = filteredchangelog
 
     return cl