diff --git a/doc/configuration.txt b/doc/configuration.txt
index 3b6d56e..16aa228 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -671,6 +671,8 @@
    - tune.maxrewrite
    - tune.pattern.cache-size
    - tune.pipesize
+   - tune.pool-high-fd-ratio
+   - tune.pool-low-fd-ratio
    - tune.rcvbuf.client
    - tune.rcvbuf.server
    - tune.recv_enough