diff --git a/mercurial/chgserver.py b/mercurial/chgserver.py
--- a/mercurial/chgserver.py
+++ b/mercurial/chgserver.py
@@ -83,6 +83,7 @@ def _hashlist(items):
     b'eol',  # uses setconfig('eol', ...)
     b'extdiff',  # uisetup will register new commands
     b'extensions',
+    b'fastannotate',  # affects annotate command and adds fastannonate cmd
     b'schemes',  # extsetup will update global hg.schemes
 ]