extra
diff --git a/include/venti.h b/include/venti.h
index 1b239af..c4538a9 100644
--- a/include/venti.h
+++ b/include/venti.h
@@ -430,6 +430,7 @@
 void vtblockduplock(VtBlock*);
 
 extern int vtcachencopy, vtcachenread, vtcachenwrite;
+extern int vttracelevel;
 
 /*
  * Hash tree file tree.