diff --git a/mercurial/wireprotov2peer.py b/mercurial/wireprotov2peer.py
--- a/mercurial/wireprotov2peer.py
+++ b/mercurial/wireprotov2peer.py
@@ -325,6 +325,8 @@
                 raise e
 
             return
+        elif action == 'noop':
+            return
 
         if frame.requestid not in self._requests:
             raise error.ProgrammingError(