diff --git a/src/config.cpp b/src/config.cpp
index 554d3685..67b84544 100644
--- a/src/config.cpp
+++ b/src/config.cpp
@@ -264,6 +264,9 @@ Config::Config()
     _map["splice_read"] =
     _map["splice_write"] =
     _map["use_ino"] =
+    _map["direct_io"] =
+    _map["kernel_cache"] =
+    _map["auto_cache"] =
     &_dummy;
 }