diff --git a/src/python/grpcio/grpc/_server.py b/src/python/grpcio/grpc/_server.py
index 20e356f73dadd21fa7cbfeeeaf572829f626148a..bf20f15f7291fd66f555b61d2b5d4babb1129e0d 100644
--- a/src/python/grpcio/grpc/_server.py
+++ b/src/python/grpcio/grpc/_server.py
@@ -344,10 +344,9 @@ def _unary_request(rpc_event, state, request_deserializer):
             if state.client is _CLOSED:
               details = '"{}" requires exactly one request message.'.format(
                   rpc_event.request_call_details.method)
-              # TODO(5992#issuecomment-220761992): really, what status code?
               _abort(
                   state, rpc_event.operation_call,
-                  cygrpc.StatusCode.unavailable, details)
+                  cygrpc.StatusCode.unimplemented, details)
               return None
             elif state.client is _CANCELLED:
               return None