diff --git a/hgext/fastannotate/protocol.py b/hgext/fastannotate/protocol.py
--- a/hgext/fastannotate/protocol.py
+++ b/hgext/fastannotate/protocol.py
@@ -221,7 +221,7 @@
 
 def clientreposetup(ui, repo):
     _registerwireprotocommand()
-    if isinstance(repo, localrepo.localrepository):
+    if repo.local():
         localreposetup(ui, repo)
     # TODO: this mutates global state, but only if at least one repo
     # has the extension enabled. This is probably bad for hgweb.