diff --git a/src/config.hpp b/src/config.hpp
index d0a81e51..a11f4592 100644
--- a/src/config.hpp
+++ b/src/config.hpp
@@ -101,6 +101,7 @@ public:
   ConfigUINT64   cache_statfs;
   ConfigBOOL     cache_symlinks;
   Categories     category;
+  TFSRef<bool>   debug;
   ConfigBOOL     direct_io;
   ConfigBOOL     direct_io_allow_mmap;
   ConfigBOOL     dropcacheonclose;