diff --git a/lib/thread.h b/lib/thread.h
index f693ff5..0670a89 100644
--- a/lib/thread.h
+++ b/lib/thread.h
@@ -80,6 +80,7 @@
     struct timeval sands;	/* rest of time sands value. */
   } u;
   RUSAGE_T ru;			/* Indepth usage info.  */
+  struct cpu_thread_history *hist; /* cache pointer to cpu_history */
   char* funcname;
 };