diff --git a/include/trace/events/iocost.h b/include/trace/events/iocost.h
index d86ff25b8dc7c18b91f7021273cc89051f6418dc..c2f580fd371b11e117be68238c8530bd88a84d1f 100644
--- a/include/trace/events/iocost.h
+++ b/include/trace/events/iocost.h
@@ -2,6 +2,10 @@
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM iocost
 
+struct ioc;
+struct ioc_now;
+struct ioc_gq;
+
 #if !defined(_TRACE_BLK_IOCOST_H) || defined(TRACE_HEADER_MULTI_READ)
 #define _TRACE_BLK_IOCOST_H